[2025-12-14]Reddit评论区：如果现在的中国穿越回二战初期，那么能在1939年征服整个世界吗？

padorUWU
Imagine present day China secretly developed a time machine that is able to telerport the entire country back and replace the old China during WW2. China will teleport back along with the entire military, citizens, infrastructure, vehicles etc. including Chinese owned satellites, radio towers, naval yards and everything underneath the ground like established pipelines. Neither allies nor the axis power see this coming. Could it conquer the world in 1939?

想象一下，现在的中国秘密研制出了一台时光机，能够将整个国家传送回去，取代二战时期的旧中国。将和全体军队、公民、基础设施、车辆等一同被传送回去，包括中国拥有的卫星、无线电塔、造船厂以及地下已建成的管道等一切设施。同盟国和轴心国都没有预料到这一切。它能在1939年征服世界吗？

watawataoui
Dude, they have 800 nukes..

哥们，他们有800枚核弹啊..

PeculiarPangolinMan -> watawataoui
And like half+ of the world population. There were only like 2.3 billion people back then.

当时全球人口才23亿左右，现在都翻倍不止了。

Suspicious_Wait_4586 -> watawataoui
So what? You can conquer some land by nuclear threat. Then what? How do you control it? Or you nuke them all? Ok, then what?

那又怎样？用核威胁抢点地盘。然后呢？怎么管？全炸光？行啊，再然后呢？

mattio_p -> Suspicious_Wait_4586
Give them TikTok and watch them pacify themselves

给他们TikTok，看他们怎么把自己安抚得服服帖帖。

statyin
Lol, of course it can be done, are you kidding?
Imagine how people were panicking about the V2 rockets made by the Germans during WWII, now imagine guided missiles and rockets being used during WWII era. There is simply no counter to that. Not to mention the drastic technological gap between modern day fighter jets and tanks compared to those in WWII era.

哈哈，这当然能做到，你在开玩笑吗？
想想二战时德国V2火箭就把大家吓成什么样，现在要是把制导导弹和火箭放到二战时期用，根本没法防御。更别说现代战斗机和坦克跟二战时期的科技差距有多大了。

risingstar3110 -> statyin
Drones warfare too

无人机作战也是。

ChiggedyChong
Modern missiles obliterate every single other countries navy and airbases. China sends spy drones and satellites, wipe out industrial centers and political leaders too, not a single person is even aware it is China.
Then it becomes a question of how they want to pacify conquered populations: riot control focused army, or computer age goods to buy them out. Just enough to seize resource locations and begin extraction, anywhere from a few months to a year in emergency conditions.
Cue an Operation Barbarossa level of ground war destruction against anyone who stands up to them. Super long range artillery, drones, invincible tanks, jet strike fighters, full mechanization.

现代导弹直接摧毁所有国家的海军和空军基地。中国派出间谍无人机和卫星，连工业中心和政治领袖也一锅端，根本没人发现是中国干的。
接下来的问题就变成他们想怎么安抚被征服的民众了：是用专门镇压暴乱的军队，还是用高科技产品收买。只要控制住资源产地并立即开采，紧急情况下几个月到一年就能搞定。
要是有人敢反抗，直接发动巴巴罗萨行动级别的陆地战争。超远程火炮、无人机、无敌坦克、喷气式战斗机、全机械化部队齐上阵。

rAdvicePloz -> ChiggedyChong
I agree 100% but I think people would readily figure out it was China when anyone who visits the country notes that they seem to have magically sprinted nearly a century forward in tech.

我完全同意，不过我觉得人们很快就能猜到是中国——只要去过那儿的人都会注意到，他们的科技像施了魔法一样飞跃了近一个世纪。

ChiggedyChong -> rAdvicePloz
By the time they do figure out it, the strikes will be complete.

等他们搞明白，打击早就结束了。

PenteonianKnights -> ChiggedyChong
Pacification would be extremely easy. People are more than willing to welcome new overlords for superior goods and quality of life.

安抚民心太容易了。只要给更好的商品和生活质量，人们巴不得换新主子。

The_Z-Machine -> PenteonianKnights
I think the Taliban would answer differently.

我觉得塔利班的回答会不一样。

taw
1939 world had 2.3b people (but 400b of that was China, so 1.9b rest of the world) and $1.3t GDP (5% of that China, so no need to adjust). China has 1.4b people and $19t GDP today.
So time travelled China would have:
40% of total world population
93% of total world GDP
absolutely insane tech advantage, in military tech, and every other possible tech
Any resistance would be the kind of slaughter last seen in 1800s battles between Brits with gatling guns and African with spears.
It's so overwhelming that there wouldn't even be much conquest to do, countries would be lining up to negotiate terms of surrender right away.

1939年全球23亿人口（其中中国4亿，其他国家19亿），全球GDP1.3万亿美元（中国占5%，基本可忽略）。如今中国14亿人口，GDP达19万亿美元。
所以穿越回去的中国将拥有：
全球40%的人口
全球93%的GDP
军事科技等各领域形成碾压级技术优势
任何抵抗都会像19世纪英国人用加特林机枪对阵非洲长矛那样单方面屠杀。
这种优势太压倒性了，根本不需要征服，各国会排队来谈判投降条件。

Rexpelliarmus -> taw
There would be no negotiation. Whatever China demanded, every country would roll over and accept or be assimilated or obliterated.

中国提什么要求，各国都得乖乖接受，不然就被同化或者消灭。

Cill-e-in
Yes, but it will be by hitting government buildings on day 1 with ICBMs and then annihilating conventional forces in-theatre, and everyone else submitting at that point.

是的，但第一天会用洲际导弹打击政府大楼，然后消灭战区内的常规部队，其他人到时候就会投降。

CanderousGordo82
Via nuclear submission, yes.
If nukes aren't allowed, then via traditional military conquest, no. It's not possible to occupy and subjugate the entire world. China also doesn't have anywhere approaching the required size military or economy to do this. The US couldnt do it with a larger military and larger economy. Even if they thought that they could, they would need time to build a LOT more shipping capability before they can extend their military domination overseas.
Diplomatically/Economically? Yes. Offer modern tech and trade agreements to other countries to sign fealty treaties and threaten nuclear destruction to anyone that refuses.

用核武器的话，能。
如果不允许用核武器，靠传统军事征服，不能。占领并统治整个世界是做不到的。中国既没有足够规模的军队，也没有足够的经济实力来实现这个目标。美国军力更强、经济更发达也做不到。就算他们自以为能行，也需要花时间建造大量运输工具才能把军事力量投送到海外。
外交和经济手段呢？能。用现代技术和贸易协定吸引其他国家签附属条约，谁敢拒绝就威胁用核武器消灭他们。

JJNEWJJ -> CanderousGordo82
I think in this scenario China would do better than the US in occupation.
The gap in tech between modern China and 1940s world is much, much bigger than the gap between modern China and modern USA. In terms of outright conquest, there would be almost no difference between China and USA conquering the 1940s world. But, in terms of population, China has 3.5 times the population of the US, and more than half of the world population at the time. They would have far more manpower available for occupation.

我觉得这种情况中国占领能力会比美国强。
现代中国和1940年代世界的科技差距，比现代中国和现代美国的差距大太多了。要说直接征服，中美征服1940年代世界没啥差别。但论人口，中国人口是美国3.5倍，比当时全球一半人口还多。他们可用的人力资源多得多。

Zestyclose_Use7055 -> JJNEWJJ
On the other hand they’ll have to feed that population without the modern infrastructure to import foreign food products at scale for that population. In contrast to the US, their land can’t support its population in its current size. They would have to conquer and enslave nearby territories quickly to provide enough supplies before moving farther out. Which they can probably accomplish with modern tech, but how long does that tech last. Will they be able to upkeep it at scale with the lack of global infrastructure? Just because china goes back in time doesn’t mean the mines they source from around the world do.

另一方面，他们得在没有现代基础设施、无法大规模进口粮食的情况下养活那么多人。跟美国不同，他们现有的土地根本养不活现在这么多人口。他们得赶紧征服奴役周边地区，抢够物资才能继续扩张。虽然靠现代科技应该能做到，但这些设备能撑多久？全球供应链断了，他们还能大规模维护这些技术吗？中国穿越了，可他们在全世界的矿场又没跟着一起穿。

VerminSupreme6161 -> Zestyclose_Use7055
China is a self-sufficient country, their current land can absolutely support their current population. The only reason they import so much food today is because they can, and because they’re also one of the largest food exporters in the world. Same thing with raw materials, China wouldn’t need to source from mines all around the world if they didn’t need to manufacture everything the world uses. In this scenario, if we ignore the economic repercussions and just focus on the war, they would have more than enough of what they need.

中国是个自给自足的国家，现有土地完全能养活现有人口。现在大量进口粮食纯粹是因为有这个能力，而且他们还是世界最大粮食出口国之一。原材料也是同样道理，要不是需要制造全球使用的各种产品，中国根本不需要从世界各地采购矿产。单从战争角度考虑，不考虑经济影响的话，他们需要的物资绰绰有余。

Ill-Engineering8205 -> Zestyclose_Use7055
Even if China has to bring its production down to a halt they have more than enough resources and manpower to keep their position. Also it wouldn't really take that long to synthetize many raw materials, not when you can demand anyone send you anything. Their navy would be the fastest in the world too.
Biggest issue would be a potential drop in population due to panic + food as you mention, but it will be fixed relatively quickly. Out of all societies honestly China is the best one suited for the "being thrown back in time" task. They can go isolationist as they have done many times to sort out internal affairs. It's not like the US for example where the average person cannot conceive a world where they are basically the only ones. China has that built into their cultural genome via being the main world power for millenia.

就算中国生产停摆，他们也有充足的资源和人力维持地位。合成原材料也花不了多长时间——毕竟可以要求任何国家提供物资。他们的海军也会成为全球最快的。
最大的问题可能是恐慌和粮食短缺导致人口下降，但很快就能解决。说实话，在所有社会中，中国最适合“穿越回去”这个任务。他们可以像以前多次那样采取孤立主义，先处理内部事务。不像美国，普通人根本无法想象世界上只剩自己的场景。中国几千年来一直是世界主要强国，这已经融入他们的文化基因。

Rexpelliarmus -> CanderousGordo82
What? This is completely nonsensical. How does this shit get upvoted?
Modern China has an economy far larger than the entire world combined in 1939. Their manufacturing output would dwarf any other power, including the US given the Chinese would have the added benefit of decades of technological advancements and automation on their side.
They’d be pumping out modern ships like crazy. A single carrier strike group consisting of the Type 003 carrier and around half a dozen destroyers and cruisers as escorts would literally mop up the entirety of the US Navy at its peak without even breaking a sweat.
The PLAAF with its thousands of modern fighter jets would sweep through the skies and China’s vast manpower would allow them to sweep through vast swathes of areas.
The world population in 1939 was 2.3B. Modern China had a population over half that at 1.4B.
The current PLAN could literally sail up to the West Coast and bomb and destroy the entire region, obliterating half the US economy in the process before the US had a chance to properly ramp up, not that it would matter because they’d just be producing garbage.
The US Navy had 15 battleships in 1939. They’re all being sunk within the first few days of contact.
China rolfstomps the entire world and it’s not even a contest.
You’re talking about bringing one of the world’s most populous countries in the modern day back to 1939 with modern day advantages in manufacturing at scale.
This is baby versus nuclear bomb.

这简直胡说八道。这种垃圾内容怎么还有人点赞？
现代中国的经济体量比1939年全球总和还大得多。他们的制造业产能会碾压任何强国，包括美国，毕竟中国还拥有几十年的技术进步和自动化优势。
他们会疯狂生产现代军舰。单是一个由003型航母加上六七艘驱逐舰巡洋舰组成的打击群，就能轻松全歼巅峰时期的美国海军，连汗都不用出。
解放军空军几千架现代战机会横扫天空，中国庞大的人力资源能让他们席卷大片区域。
1939年世界人口23亿，现代中国人口就超过一半达到14亿。
现在中国海军可以直接开到西海岸狂轰滥炸，在美国来得及全面动员前就摧毁半个美国经济——不过他们就算动员也没用，造出来的都是垃圾。
1939年美国海军有15艘战列舰？开战头几天就会全部沉没。
中国完全碾压全世界，根本毫无悬念。
你这是要把现代世界人口大国送回到1939年，还带着现代规模化制造的优势。
这简直是婴儿VS核弹。

Dpek1234 -> Rexpelliarmus
And yet the chinese military simply isnt setup for power projections
No matter how advanced your weapons, you need to actualy get them there
Its very questionable if china could get such a capability in a mere year

然而中国军队根本就没为力量投射做好准备
不管武器多先进，你得真能把它们运过去
中国能不能在短短一年内获得这种能力很成问题

Rexpelliarmus -> Dpek1234
China has the world’s largest merchant navy. Why do you think they couldn’t commandeer these vessels to act as the world’s largest AOR fleet in history to replenish vessels at sea and help them project power?
China’s navy not being set up for power projection now is not a matter of capability but a matter of China not caring about power projection at the moment. Nothing is stopping them from commandeering a few dozen of their tankers and cargo vessels for military use.
A cargo ship capable of transporting hundreds of thousands of tonnes of TEUs is going to be able to transport thousands of tonnes of military equipment.

中国商船规模全球第一，为啥不直接征用它们搞成史上最大补给舰队，帮海军在海外投射力量？
中国海军现在不搞力量投射，不是能力不够，而是压根没这打算。真要动手，随便征用几十艘油轮货船改军用的障碍根本不存在。
一艘能运几十万吨集装箱的货轮，运几千吨军用装备还不是小菜一碟。

Live-Cookie178 -> Rexpelliarmus
Americans have somehow truly deluded themselves into believing that a country running massive supply chains on the daily basis cam’t figure out how to handle basic logistics.

美国人真是迷之自信，居然觉得一个天天运转庞大供应链的国家搞不定基础物流。

Rexpelliarmus -> Live-Cookie178
They somehow think the US invented logistics and only the US can do them well as if the modern world doesn’t run off just-in-time logistics that is predominantly run and operated by China…

他们居然以为物流是美国发明的，只有美国能做好，却忘了如今全球依赖的准时制物流体系，其实大半是中国在运营...

Pklnt -> CanderousGordo82
China also doesn't have anywhere approaching the required size military or economy to do this.
Modern day China in the 40s would smash everyone in less than 5 years.
The issue is whether or not they'd be able to manage conquered territories. But militarily they'd have absolutely no problem projecting forces where they want.
I'd be like Iraq all over the world, the government and the military gets destroyed in a week, but the biggest issue is how well they'd administer the new territories and how hard would the local population resist the Chinese. If we assume the world population doesn't want the Chinese presence, China can't win.
However, militarily, WW2 Submarines or planes simply do not have the capability to prevent anything. China could literally retrofit a container ship with hundreds of thousands of FPV drones and slaughter any resistance miles away from a predetermined bridgehead.

“中国既没有足够规模的军队，也没有足够的经济实力来实现这个目标”
但要是把今天的中国放到40年代，五年内就能横扫全球。
问题在于他们能不能管好打下来的地盘。但军事上他们想往哪儿派兵都没问题。
这就像伊拉克战争在全球重演，政府和军队一周内就会被摧毁，但最大的麻烦是怎么治理新占领的地区，当地人会怎么反抗中国人。如果全世界都不接受中国人来管，那中国赢不了。
不过单从军事角度看，二战时期的潜艇飞机根本挡不住任何东西。中国随便改装一艘货船就能装上几十万架无人机，在预设的桥头堡几英里外就把抵抗力量全灭了。

Angry_beaver_1867 -> Pklnt
Population matters to. Global population was around 2b excluding China.  
China would have a the ability to overwhelm any country they where fighting.  

人口同样关键。全球人口（不含中国）大约20亿。
中国有能力碾压任何与之交战的国家。

ZealousidealDance990 -> Pklnt
I don't think management is a problem. China now has 1.4 billion people, a large portion of whom have received basic education. Back then, the world only had 2 billion people. As long as people are deployed around the world, management won't be too difficult.

我不认为管理是个问题。中国现在有14亿人口，其中很大一部分都受过基础教育。而当时全球只有20亿人。只要把人员部署到世界各地，管理就不会太难。

Ill-Engineering8205 -> ZealousidealDance990
You don't need that many people to occupy a region. Honestly for the numbers difference China can just send a small contingent of enough people to be like 5% of the local population and give a strong incentive to multiply. Easiest replacement ever when you have 2020s medicine and everyone else doesn't.
They can play the game at the fastest speed in integration and still win.

根本不需要那么多人去占领一个地区。说真的，就凭人口差距，中国派支小分队过去，人数达到当地人口的5%左右，再给足生育激励就够了。在别国医疗落后的情况下，用现代医疗手段搞人口替换简直易如反掌。
他们完全可以用最快速度推进融合进程，照样能赢。

Sevsquad -> Pklnt
But militarily they'd have absolutely no problem projecting forces where they want.
This is not by any means a given. I think the United States has given people a very skewed idea of how easy force projection half way across the world is. The network of logistics hubs the US military uses to supply it's troops took literal decades to construct. Without it things like the US invasion of Iraq would have been literally impossible.

“但军事上他们想往哪儿派兵都没问题”
这可不是理所当然的事。我觉得美国给人们灌输了错误观念，让人以为隔着半个地球投送军力很容易。美军用来补给部队的后勤枢纽网络花了几十年才建成。没有这个网络，像美国入侵伊拉克这样的行动根本不可能实现。

Pklnt -> Sevsquad
It is a given.
We're talking about a country whose military would be nearly a century more advanced than the most advanced militaries in the 40s.
Not only that, but the PLAN today is far more capable than the US Navy in the 40s, that means no potential battle of the Atlantic or a Pacific war here, any enemy warship would be destroyed and modern ASW capabilities would make any WW2 submarine completely worthless.
There is no threat here, convoys would arrive where they'd need to arrive because a single Chinese Warship would project an anti submarine/air bubble that would make any attempt at disrupting it impossible.
China would have absolutely no problem landing where they want to land by virtue of having such an insurmountable advantage against any potential force trying to prevent that.
This is where force projection is no longer difficult, it's just a matter of shipping equipment and goods where it needs to go, and the Chinese are already masters at it. Force projection is extremely complicated in a non-permissive environment, by virtue of being so out of anyone's league, China would simply evolve in a very permissive environment, there is almost no disruption of your logistical chain here. That is until guerrilla sets in, but I think I already addressed that point.
Furthermore, China already prepares the necessary ships to make bridgeheads against Taiwan, doing the same against the USA/Europe in the 40s would be a walk in the park.
Not only that, but their industrial output is absolutely ridiculous, they could literally wipe any 40s military off the earth by just building hundreds of thousands of FPVs.
Not only that, but their shipbuilding capabilities is also completely insane. In one year they output more tonnage than the US did during WW2. And that's China with a peace-time economy.

这是明摆着的事。
我们讨论的这个国家，其军事实力比上世纪40年代最先进的军队领先近一个世纪。
不仅如此，如今的中国海军实力远超40年代的美国海军，这意味着大西洋海战或太平洋战争不会重演，任何敌舰都将被摧毁，现代反潜能力让二战时期的潜艇毫无用武之地。
根本不存在威胁，运输船队可以安全抵达目的地，因为仅一艘中国军舰就能构建反潜/防空保护圈，任何破坏企图都是徒劳。
中国完全可以在任何想要的地点登陆，面对任何试图阻挠的势力都具有压倒性优势。
在这种情况下，力量投送不再困难，只需把装备物资运到指定地点，而中国人对此早已驾轻就熟。在非许可环境下力量投送极其复杂，但由于实力差距悬殊，中国相当于在完全许可的环境下行动，后勤链几乎不会受到干扰。除非遭遇游击战，不过这点前面已经讨论过了。
更何况，中国已经备好了在台湾建立桥头堡所需的舰船，要在40年代对美国/欧洲做同样的事简直易如反掌。
不仅如此，中国的工业产能简直离谱，他们单靠生产几十万架FPV无人机就能彻底消灭40年代的任何军队。
更离谱的是他们的造船能力。和平时期中国一年的造船吨位就超过美国二战期间的总和。

DivideMind -> Pklnt
Wonderful post, I wanted to discuss how people here seem to be severely undervaluing the pillar of modern industry equipped with modern weapons, but you hit all the points. A single, say, Italian destroyer (especially the new heavier ones being built) with industrial backing could make a burning wreck out of a WW2 navy trying to intercept convoys, nevermind the literal might of the entire PLN.
It's almost comparable to an actual galactic empire showing up here, except at least we can likely effectively observe them as they destroy us (unless they decide to use a WMD).

很好的内容！我本来想讨论这里的人严重低估了现代工业支柱配合现代武器的威力，但你把要点全说透了。一艘意大利驱逐舰（特别是正在建造的新型重型舰）在工业体系支持下，能把拦截船队的二战海军打成燃烧的废铁，更别提中国海军的绝对实力了。
这差不多就像银河帝国降临地球，至少我们还能眼睁睁看着自己被摧毁（除非他们动用大规模杀伤性武器）。

Marino4K -> Pklnt
We also have no idea what top secret tech could be available to China.

我们也不知道中国可能掌握什么绝密技术。

TheShadowKick -> Pklnt
Not only that, but the PLAN today is far more capable than the US Navy in the 40s
I have to disagree with this. Their ships are more advanced and would easily win battles, but they don't have the force projection capabilites of the US Navy in the 40s. It's not just about keeping your convoys safe, logistics requires significant infrastructure and planning to support a large military force.
China could certainly build the necessary logistics capability and nobody in the 1940s could stop them, but they don't currently possess it.

“不仅如此，今天的中国海军远比40年代的美国海军强大”
我不同意这个观点。他们的军舰确实更先进，打海战肯定能轻松取胜，但现在的中国海军不具备40年代美国海军的兵力投送能力。打仗不光是保护运输船队这么简单，后勤保障需要大量基础设施和周密规划才能支撑大规模部队。中国当然有能力建设必要后勤体系，40年代也没人能阻止他们，但眼下他们确实还不具备这种能力。

Rexpelliarmus -> TheShadowKick
A single Chinese cargo vessel and tanker can carry more equipment and fuel than the entirety of the USN’s AOR fleet in the 1940s.
You underestimate how big ships of this kind have gotten. The USN needed such a large network because their AOR ships were inefficient and tiny. China just needs to have 2-3 vessels and they’d ship enough materiel to obliterate any opposing force.
The world’s militaries would be completely neutralised in 2-3 months.

一艘中国货船和油轮能装的装备和燃料，比1940年代美国海军整个补给舰队还多。
你低估了这类船现在有多大。美国海军当年需要那么庞大的补给网络，是因为他们的补给船又小又低效。中国只需要两三艘船，就能运送足够摧毁任何敌对力量的物资。
全球军队在两三个月内就会彻底失去战斗力。

TheShadowKick -> Rexpelliarmus
That's not how logistics works. It's not just a matter of having big enough ships. This isn't a video game.

物流不是这么运作的。光有大船可不够。这又不是打游戏。

Rexpelliarmus -> TheShadowKick
That is how logistics works when there is no threat to your shipping. China has hundreds of massive oil tankers and enormous cargo ships. What is stopping them from using these ships as merchant ships to transports hundreds of tonnes of equipment, troops, fuel and personnel?
There is no threat to these ships. They could literally ship shit around like commercial vessels currently do at a scale the USN has never matched in history.
Who do you think keeps global modern supply chains running? China with their supply chain logistics and massive merchant tanker and cargo fleet. You thought USN logistics was impressive? Wait till you see how much shit China has been shipping around the world for decades.
Replace those TEUs with tanks, ammunition crates, IFVs, helicopters, literally anything you could ever want.
The PLAN does not build out its power projection capabilities only because China does not want to because there is no need. They have the world’s largest merchant navy on the planet. What is the need?

这就是没有航运威胁时的物流运作方式。中国拥有数百艘巨型油轮和大型货轮。有什么能阻止他们用这些商船运输数百吨装备、部队、燃料和人员？
这些船根本不受威胁。他们完全可以像现在的商船那样大规模运输物资，这种规模是美国海军历史上从未达到过的。
你以为现代全球供应链靠谁维持？靠中国的供应链物流和庞大的商船油轮船队。你觉得美国海军后勤很厉害？等你看看中国几十年来在全球运输了多少物资再说吧。
把那些集装箱换成坦克、弹药箱、步兵战车、直升机，任何你想要的装备都行。
中国海军不发展力量投送能力，纯粹是因为中国不想这么做，也没这个必要。他们拥有全球最大的商船队，还需要什么呢？

ychwee -> TheShadowKick
How would they not have the force projection capabilities? They can literally sail container ships around anywhere in the world escorted by a single destroyer.
A Panamax sized container ship already has more than 5x DWT of a Liberty ship not to mention larger container ships. Attach 2 Panamax container ships to any amphibious force and you have enough oil, munitions, logistical capacity to take over any small country in WWII.
On land? Just churn out 1960s era trucks by the hundreds of thousands. Save the MBTs for escorts, just some APCs or a drone will do.
On air? Y-20 transport aircraft can fly above anything thrown at them in WWII. Actually, you don't even need that, just send out passenger aircraft.
The only (very minimal) casualties will be from establishing a beachheard or capturing an airport, and getting it up to scratch for modern aircraft to land.
In a peer war, logistical buildout is slower because of the need to properly defend, harden, allocate capacity and buffer for losses. There is no need to do so here.

他们怎么可能没有力量投送能力？随便派艘驱逐舰护航，集装箱船就能开到世界任何角落。一艘巴拿马型集装箱船的载重吨位已经是二战自由轮的5倍以上，更别说更大的集装箱船了。给任何两栖部队配两艘巴拿马型集装箱船，携带的油料、弹药和后勤物资就足够在二战时期占领任何小国。
陆地作战？直接量产几十万辆1960年代的卡车就行。主战坦克留着护航用，有几辆装甲运兵车或无人机就够了。
空中运输？运-20运输机能在二战时期的任何防空火力上空飞行。其实连这个都不需要，直接派客机就行。
唯一可能出现的轻微伤亡只会发生在抢滩登陆或占领机场的时候，需要把机场整修到能让现代飞机降落。在势均力敌的战争中，由于需要严密防守、加固设施、分配运力并预留损失缓冲，后勤建设会比较慢。但在这情况完全没必要考虑这些。

Jahobes -> Sevsquad
This is not by any means a given. I think the United States has given people a very skewed idea of how easy force projection half way across the world is.
It's an absolute given bro. It would be worse than Iraq in the 90s it would be more like Panama in the 80s but all over the world.
There are entire weapons platforms that are completely untouchable. The worst tank that China could field doesn't even need ammunition to kill tanks from the 40s. It could go around running over Sherman's and Tigers like monster trucks and there is nothing outside of a giant field artillery piece that could even dent modern tank armor.
Their fucking attack helicopters would be able to dog fight with WW2 fighter planes at low to medium altitude... Jets would just be death from the skies without anyway for anyone to retaliate.
Most soldiers in the 40s were using semi automatic rifles... Shit even the mujahideen had fully automatic rifles for their fighters... Every engagement at the squad level and above is just a slaughter.
The network of logistics hubs the US military uses to supply it's troops took literal decades to construct.
The US conquered Europe and the Pacific without those bases against peers in 1940. Bro, China will be able to set up a base where ever and when ever they want and once they arrive their is nothing to dislodge them.

“这可不是理所当然的事。我觉得美国给人们灌输了错误观念，让人以为隔着半个地球投送军力很容易”
老兄，这绝对是板上钉钉的事。情况会比90年代的伊拉克还糟，更像是80年代巴拿马那种局面，只不过会席卷全球。
中国有些武器平台根本无人能敌。他们最差的坦克就算不用弹药，也能轻松摧毁40年代的坦克，直接像怪兽卡车一样碾过谢尔曼和虎式坦克。除了巨型野战炮，没有什么武器能在现代坦克的装甲上留下哪怕一点凹痕。
他们该死的武装直升机，甚至能在中低空跟二战战斗机狗斗... 喷气式战机简直就是来自天空的死神，对方根本无力还击。
40年代大多数士兵用的还是半自动步枪...妈的，连圣战分子都人手全自动武器... 班排级以上的每次交火都纯粹是单方面屠杀。
“美军用来补给部队的后勤枢纽网络花了几十年才建成”
美国在1940年没有这些基地的情况下就征服了欧洲和太平洋。老兄，中国想在哪建基地就能在哪建，想什么时候建就什么时候建，一旦他们抵达，就没人能赶走他们。

bcpl181 -> Jahobes
I virtually agree with everything you said, except that the US did have a base in WWII to invade Europe. They had the UK. Without the UK, it would have been a much more difficult undertaking.

我基本同意你说的所有观点，但美国在二战时确实有个进攻欧洲的基地，那就是英国。没有英国的话，这事会难办得多。

Rexpelliarmus -> Sevsquad
China would be able to set up supply bases across the planet within a few months completely uncontested because the RN, USN and IJN would have had the entirety of their fleets sunk in the first month of conflict.
The Type 055 destroyer, of which the PLAN has 8 and is building 8 more, could literally destroy half or even all of the USN’s battleship fleet on its own simultaneously.

中国几个月内就能在全球建立补给基地，因为英国、美国和日本海军舰队在冲突第一个月就会全军覆没。
中国海军现役8艘055型驱逐舰，还有8艘在建。单单一艘055就能同时摧毁美国海军一半甚至全部战舰。

RaceHard -> Pklnt
And if China did not care about non-chinese people living? Ie they plan to wipe out every other human via non-nuclear means, non-biological either.

如果中国不在乎外国人的生命呢？比如他们计划用非核、非生物手段消灭其他所有人类。

TheShadowKick -> Pklnt
Modern day China doesn't have the force projection to smash everyone and it would take them more than 5 years to build up to it. It doesn't matter how superior your technology is if you can't get your soldiers to where the enemy is.

现代中国没有碾压所有人的力量投射能力，要建立这种能力至少需要五年以上。技术再先进，士兵到不了敌人面前也是白搭。

VerminSupreme6161 -> TheShadowKick
They wouldn’t need to attack everywhere simultaneously, this isn’t a Zerg rush. Amphibious forces would take the entire Pacific while land forces can cross into Eurasia. From there they can pick and choose from the rest of the globe.

他们根本不需要同时进攻所有地方，这又不是虫族突袭。两栖部队能拿下整个太平洋，陆军还能横跨欧亚大陆。到时候全球其他地区还不是随便他们挑。

kenzieone -> CanderousGordo82
I do think that the latter option blends into military coercion fairly seamlessly and would be much easier than we might think. They could offer ancient surplus radars to countries that blow away the secret stuff Britain was cooking up. Their sheer productivity is like nothing 1939 had seen thus far; they could probably supply the entire world with consumer goods far in advance of 1939 standards and in excess of 1939 abundance.
Sure, some countries at the time were extremely ideologically driven and wouldn’t immediately cave. But after a few dozen precision bombing runs, they negotiate with whoever is left standing and make the fairly credible offer that they’ll stop bombing, remove all threat of invasion, and comprehensively upgrade every facet of that countries infrastructure and economy, including the lives and healthcare of their citizens.
Most countries would take that deal, particularly the colonial governments chafing under foreign rule at that time.
Also, the OP did not specify prep time, but did note that this was planned. Frankly with chinas shipbuilding capacity and profound tech advantage, not to mention considerable fraction of the 1939 world population, I think that means that invading North America is plausible, given that they could take time to build up that sort of blue water force (though their current navy could solo the worlds 1939 navies no problem). Maybe not landings in LA itself, but establishing footholds in rural areas, south and Central America, Alaska etc, and using them + carriers to launch long distance raids that are 4 generations beyond any fighters the US has. If they landed in Baja California and established a base to begin methodically dismantling the war making power of North America, they have the long-distance fires to prevent any plausible attack on said base.

我觉得后一种选择其实很容易就变成军事胁迫，而且比我们想的要简单得多。他们可以把老旧的雷达送给那些能破解英国秘密武器的国家。他们的生产效率在1939年是前所未见的，估计能向全世界供应远超1939年标准和数量的消费品。
当然，当时有些国家意识形态至上，不会立刻屈服。但只要进行几十次精准轰炸，他们就能和剩下的人谈判，提出相当可信的条件：停止轰炸，消除所有入侵威胁，全面升级该国基础设施和经济，包括改善民生和医疗。
大多数国家都会接受这个交易，尤其是当时那些受外国统治的殖民地政府。
另外，题主没说明准备时间，但提到这是有计划的。说实话，以中国的造船能力和巨大技术优势，更不用说占了1939年相当大部分的世界人口，我觉得入侵北美是可行的。他们可以花时间组建远洋舰队（虽然现在的海军单挑1939年全球海军也没问题）。可能不会直接在洛杉矶登陆，但可以在农村地区、中南美、阿拉斯加等地建立据点，用航母发动远程袭击——他们的战机比美国先进四代。如果在南下加利福尼亚登陆建立基地，他们有能力用远程火力系统性地瓦解北美的战争潜力，同时确保这个基地不受任何可能的攻击。

Shadowstar1000 -> CanderousGordo82
Even by traditional means conquest I think China takes this pretty easily. The global population in 1940 was 2.3 billion people, 300 million of which comes from China. China’s current population is 1.4 billion people. They genuinely have a large enough population to occupy the planet.

就算按传统征服方式，中国也能轻松拿下。1940年全球人口23亿，中国占了3亿。现在中国人口14亿，光靠人海就能占领整个地球。

Xylus1985
Any modern country transporting back to 1939 with all modern infrastructure and technology doesn’t need to conquer the world. The world will be knocking at their door begging to join

现代国家带着所有基础设施和技术穿越回1939年，根本不需要征服世界。全世界都会主动上门求着加入。

SwordofDamocles_
Yes, if you mean conquering the world from a start of 1939. No if you mean conquering the world by 1939.Eurasia easily, but landing somewhere north of the Darien Gap to attack the USA and Canada would be very difficult.
China's biggest issue at the start would be advancing into the East Indies and capturing any source of oil, but nothing stops the country from mining oil deposits they know exist, solving their oil problems within a year or so. A start date of 1939 means that most of the Japanese army is within 1939!China and disappears, making Japan even easier to capture. From there, they could launch an invasion of Hawaii, California, Indochina, or even Europe.

是的，如果你指的是从1939年开始征服世界。不，如果你指的是在1939年之前征服世界。欧亚大陆很容易拿下，但要登陆达连地峡以北进攻美国和加拿大就非常困难了。
中国最初最大的问题是进军东印度群岛并夺取石油资源，但没什么能阻止他们开采已知的石油矿藏，大约一年内就能解决石油问题。1939年开局意味着大部分日军都在1939年的中国境内，瞬间就会被消灭，这使得日本更容易拿下。从那里他们可以发动对夏威夷、加利福尼亚、印度支那甚至欧洲的入侵。

Jahobes -> SwordofDamocles_
Darien Gap to attack the USA and Canada would be very difficult.
Bruh, there is no place on earth that would be difficult for modern China to land if it was determined against 1940s technology.

兄弟，要是现代中国铁了心要打1940年代科技水平的国家，地球上就没哪儿是登陆不了的。

doogiehowitzer1 -> Jahobes
I mean really. What are these people in here smoking because I want some.
Modern day China could land at Mission Beach San Diego and have the entirety of California conquered within a week. From there it’s just a matter of how quickly they want to drive east.

说真的，这些人到底在吸什么，给我也来点。
现代中国要是登陆圣地亚哥使命湾，一周内就能拿下整个加州。之后就看他们想多快横扫东岸了。

Jahobes -> doogiehowitzer1
Yeah. The only threat that China would face is logistics. None of the weapons or tactics from 1940 is going to even slow down that machine.

确实。中国唯一可能面临的威胁就是后勤问题。1940年的那些武器和战术，根本挡不住这台战争机器。

doogiehowitzer1 -> Jahobes
Exactly. It would be the equivalent of an alien invasion by a race far more technologically advanced than we are.

没错。这就好比外星人入侵，他们的科技水平远超我们。

Rexpelliarmus -> doogiehowitzer1
Xi himself would be seated in the Oval Office before you could finish binge watching a TV show.

还没等你看完一部电视剧，习就已经坐在椭圆形办公室里了。

Just-Performance-666
They'd have absolutely no defense against long range missiles. And that with the modern combined arms tactics would absolutely stomp the world.

他们根本防不住远程导弹。再加上现代联合作战战术，绝对能横扫全球。

TSED
So... You said 1939.
But China was invaded and fighting in WW2 in 1937. What happens there? Is occupied China suddenly replaced with a non-occupied version of itself from 2025? Are the Japanese soldiers still there or vanished? Does Japan maintain the occupied places and everything else flips to 2025?
The answers to your questions depends greatly on how this transposition actually occurs.
If China instead teleports back in time to 1937 on the day of the Japanese invasion, then, yes. They can absolutely conquer the entire world before 1939. Heck, they might prevent "WW2" because the Nazis will see what China is up to and suddenly be more concerned about preserving their state than they are about killing some polish jewish folk.

所以...你说的是1939年。
但中国在1937年就被入侵并参与二战了。这怎么办？被侵略的中国突然被2025年未被侵略的版本取代了吗？日本士兵还在那儿，还是凭空消失了？日本能维持占领区而其他地区都变成2025年的样子吗？
这些问题的答案完全取决于时空置换的具体方式。
如果中国是在日本入侵当天穿越回1937年，那没错，他们绝对能在1939年前征服全世界。他们甚至可能阻止“二战”爆发，因为纳粹看到中国的行动后，会更关心如何自保而不是屠杀波兰犹太人。

Rexpelliarmus -> TSED
Preserving their state? They’ll be speaking Mandarin before the summer of 1938.

自保？到1938年夏天前他们就得说中文了。

Byronwontstopcalling -> TSED
Japanese soldiers resting in a Chinese village and waking up into a cyberpunk alien civilization

日本兵在中国村庄休息，醒来发现身处赛博朋克外星世界。

magus0
Assuming every country vs China, I do not think so.
The world is large, and even if they have very powerful weapons and missiles they are the aggressors which is a much harder position than holding onto territory.
Modern China will also lose one of the things that make them a major superpower if transported back in time, and that's the world's reliance on them as a trading partner which gives them incredible political and diplomatic leverage. They would just be relying on military and production capabilities, and while that is strong it's not enough to take over the entire world.

我觉得中国VS全世界不太可能。
世界很大，就算他们武器导弹再厉害，但他们是侵略者，这比守住领土要艰难得多。
现代中国要是穿越回去，还会失去一个超级大国的优势：全球对它的贸易依赖，这可是巨大的政治外交筹码。光靠军事和生产能力，虽然很强，但想统治全世界还远远不够。

Ilhan_Omar_Milf
They would empower local marxist leninist parties not try and anex the entire world

他们会扶持当地的马列主义政党，而不是试图吞并整个世界。

Suspicious_Wait_4586
I think China would stop Japan even thinking to go against China in the first place.
Then they would take control or annex most of south asia (probably whole india included) and at least control middle east (petrol reserves 40's people don't even know yet). Then they'll negociate with USSR to take Siberia or whole asian part of it (Ural mountain chain included). In exchange providing military (or political) help to gain control of some/most european territory.
And some control in other parts of the world (Australia, Chile, South Africa) to get resources. But nothing more i think

我觉得中国一开始就会阻止日本有任何对抗中国的念头。然后他们会控制或吞并大部分东南亚地区（可能包括整个印度），至少掌控中东地区（那里有40年代人们还不知道的石油储备）。接着他们会和苏联谈判，拿下西伯利亚或者整个亚洲部分（包括乌拉尔山脉）。作为交换，中国会提供军事（或政治）支持，帮助苏联控制部分或大部分欧洲领土。
还会在世界其他地区（澳大利亚、智利、南非）建立一定控制权以获取资源。
但我觉得也就仅此而已了。

Byronwontstopcalling -> Suspicious_Wait_4586
Japan would take one look at Shanghai and one look at an ICBM and immediately fold and join China as a province

日本看一眼上海，再看一眼洲际导弹，立马就怂了，直接加入中国当个省份。

NumbersOverFeelings
Japan is gone. Idk if they’d reverse revenge Unit 731, but China will drop a nuke on Japan as a demonstration and a middle finger. Maybe one on England and take Hong Kong back immediately. Going back in time gives China a hitlist of the influential and powerful.
Yeah, conquest would be relatively easy.

日本完蛋。不知道他们会不会报复731部队，但中国会往日本扔核弹作为示威挑衅。可能还会给英国来一颗，立马收回香港。穿越回去让中国有了一份有权有势者的清算名单。
确实，征服会相对容易。

Bonjour2marhaba
yes. They wouldnt even have to conquer with tanks and drones. Sats, Wifi, BYDs...they could out sell the US and win over Africa with security and food.
If for some reason the ENTIRE planet unites against them...they still "win" by having their version of the UN and controlling global trade and tech development.

是的。他们甚至不需要用坦克和无人机去征服。卫星、无线网络、比亚迪汽车…他们能靠销售超越美国，用安全保障和粮食赢得非洲。
就算整个地球莫名其妙联合起来对付他们…他们还是能“赢”，因为他们有自己版本的联合国，还控制着全球贸易和科技发展。

Positive_Rabbit_9111
They UTTERLY DOMINATE the same way a modern army beats an army from the 1800s. The tech advantage is too wide, never mind the industrial advantage.

他们会彻底碾压对手，就像现代军队暴打19世纪的军队一样。技术优势太大了，更不用说工业优势了。

Ducklinsenmayer
-Yes.
-Worst day Japan ever had, barring Godzilla.

-是的。
-会是日本历史上最糟糕的一天，除了哥斯拉那次。

Expensive_Guide_7805
There would be absoluetly no counter for Chinese air force alone.

光是中国空军，就完全没有反制手段。

solarpropietor
Yes, and very easily.   
Japan ceases to exist as a nation entirely.   And instead becomes colony of China.  They would keep the emperor alive tho as a puppet monarch.

是的，而且轻而易举。
日本将彻底不复存在，转而成为中国的殖民地。不过他们会保留天皇作为傀儡君主。

Tiny-Ask-7100
Did they also transport back all their cash? Pretty sure they could just BUY the world from 1939. No need to conquer something you already purchased.

他们是不是也把现金都带回去了？那他们完全可以直接买下1939年的世界啊。征服已经买下的东西有啥必要呢。

MXAI00D
They certainly would have kicked Japan all the way to Tokyo and we would have a picture of Chinese soldiers posing a Chinese flag on top of Hirohitos castle.

他们肯定能把日本一路打到东京，我们就能看到中国士兵在裕仁皇宫顶上插中国国旗的照片了。