Strategic thought game: Defend Korea

Let's make a defence plan for Korea. Era of use of the strategy would be WWI~WWII era(tech remain at OTL levels, although chemical weapons may be considered for the most dire of situations). Assume both China and Japan will be attacking and for the foreseeable future there will be no assistance. Further assume that China will possess strong relatively a stronger army, while Japan will possess a stronger navy. while The idea is similar to National Redoubt of Switzerland or the equivalent of Czechoslovakia.
Major points of the operation is:
  • Form multiple defensive lines from where maximum attrition against the enemy can be made, along the coast or further inland;
  • Deny the enemy from utilisation or exploitation of most if not all infrastructure and personnel, civilian or military, of Korean origin;
  • Utilise asymmetrical and irregular warfare to the fullest, if the multiple defensive lines have been breached and the government capitulated;
  • Allow for immediate pushback of battlefront form Korean territory if situation allows.
So here's my take on the game-
On China:
  • Chinese armies have traditionally struck by first crossing the Yalu river and therefore attacked from the northwest. It's assumed that it is simply hard to attack from the east, which is very mountainous
  • Kaema Plateau has not only minimal infrastructure for transport but also of relatively harsher gradient for movement of mechanised infantry; it also serves well as a point of attack for guerrilla units
  • As is obvious, first general line of defence in the west stretches along the Yalu river, ~5km inland, from Uiju to Chasong - around 200 miles. Defence in the east begins at Hoeryong, goes northeast up to Onsong, where it goes back south to the Russian border
  • The first Japanese invasion of Korea and the Korean War has proven - and general common sense shows - how effective the defensive line is if around the 39th parallel, which is the "bottleneck" of the peninsula. First line of redoubt is drawn from Chongchon River to north of Wonsan
  • When preparing for evacuation south of first line of redoubt, all military personnel and infrastructure north of the line should either be destroyed or moved south; civilians should be evacuated if a large enough food reserve exist
  • If infrastructure allows, establishment of base for possible guerrilla warfare in Kaema Plateau is also necessary; goes hand in hand with establishment of defensive line along Kilju Bottleneck to stop invasion from the northeast
  • Second line of redoubt is a few hundred miles south, along the Myroak Range, west of the Taebaek mountains while in the east every attempt should be made to keep the Seoul-Wonsan railway; if Wonsan is lost infantry is to retreat south along that line into Kangwon
  • If second line of redoubt is broken, northern front has formally reached 'breach status' and all military personnel and infrastructure north of the Imjin river should either be destroyed, moved south or modified to reach 'guerrilla' status, where they become mobile and available for camouflage
  • If battlefront has stabilised along the first line of redoubt for more than 60 days or the Chinese have taken more than 30 days to reach it, it is advised that the military attempt a strategic counteroffensive and force the enemy to retreat. The goal at this time is to surround a majority of the enemy before pushing the remainder north of the Yalu river
9Mna3Oe.png


On Japan:
  • The Japanese have historically taken two main routes for amphibious assaults in the objective to capture Seoul - from Pusan, as was during the first and second Japanese invasions of Korea; and from Kunsan, as was during the First Sino-Japanese War. It is therefore assumable that the Japanese will launch their amphibious attacks on a major port city, such as Inchon, Pusan, Kunsan, or Mokpo
  • Unlike the northern mountainous regions, the south has much less room that allows for guerrilla units to easily infiltrate behind enemy lines, although two main possibilities exist: Kangwon province, located east of Seoul, and Jiri mountain, which stands as the only mountain south of the 38th parallel, other than Cheju Mountain, to be above 1000 metres
  • The first general line of defence in the south begins in Kunsan, which is primarily comprised of submarine mines; this stretches between the small islands along the southwestern coast and ends at Pusan. For Mokpo and Pusan however, there also exist defensive lines ~5km behind the shoreline. The general line of defence in the east, which begins at Ulsan and stretches up to Wonsan in effect, is much less fortified
  • In order to show determination and effectiveness to the West, urban warfare and a "fight to the death" is encouraged in all port cities. Due to limited resources, if more than one major port city is under direct attack it is advised that at least one battlefront be retreated to the line of redoubt; the same is advised if the general line of defence of one major port city has been held for more than 90 days
  • Three lines of redoubt are drawn for each major port, except Inchon - it is hoped that extensive naval mine networks and torpedo ships are able to stop any Japanese naval attack, if one occurs. Due to limited resources if two or above lines of redoubt are forced to be held for more than 60 days, military personnel and infrastructure are to begin undergoing the process of reaching 'guerrilla' status
  • If the line of redoubt for a city is broken, southern front has formally reached 'breach status', and all military personnel and infrastructure south of the Asan bay-Sobaek range line should either be destroyed, moved south or modified to reach 'guerrilla' status, where they become mobile and available for camouflage
  • A possible naval mining operation, if given enough time, is to lay a series of naval mines between the Korean mainland and Cheju island(Quelpart). This not only buys enough time for Kunsan and Inchon to prepare its defences, but also increases the possibility of the Japanese fleet sinking due to mines and does not force the Korean fleet into a "decisive battle" situation
  • If Korea has a submarine fleet, it is advised to use the fleet to the fullest extent, attacking Japanese shipping lines and possibly even blockading the Home Islands. It is hoped that this brings the war to a quicker conclusion
4zgNt1q.png


Further notes:
  • This plan does not take into consideration the military collaboration between China and Japan - for example, amphibious landings in Wonsan or Haeju
Hope you enjoyed it. Also hoping for input and possibly alternate stretegies
 
clarify

is this an independant korean state?
is this a concurrent chinese/japanese attack? allied? belligerents?
how is korea armed?
 
Wouldn't it be possible that our hypothetical invaders from the Chinese direction might also possess significant naval and amphibious assets that could be used to outflank defense lines in the north or even open another front from the Japanese direction? What about the possibility of an amphibious invasions in the center region of the country, like Inchon in the Korean War.
 
I just don't think you can defend with WWI/II technology.

You are fighting an industrial war with 2 massively larger and probably richer nations if it becomes a war of attrition you cant win without allies....
 
is this an independant korean state?
is this a concurrent chinese/japanese attack? allied? belligerents?
how is korea armed?

This is indeed an independent Korea that controls the entire peninsula.
China and Japan are assumed to attack simultaneously, but not assumed to coordinate with each other.
It is assumed Korea is alone in this fight(with both China and Japan being the belligerents), and the objective is as mentioned:
  • Form multiple defensive lines from where maximum attrition against the enemy can be made, along the coast or further inland;
  • Deny the enemy from utilisation or exploitation of most if not all infrastructure and personnel, civilian or military, of Korean origin;
  • Utilise asymmetrical and irregular warfare to the fullest, if the multiple defensive lines have been breached and the government capitulated;
  • Allow for immediate pushback of battlefront from Korean territory if situation allows.
It is hoped that this allows "help", diplomatic/materiel support from the West or the USSR, will come eventually. The defence plan, assuming everything went along perfectly, buys Korea 180 days for an agreement on ceasefire or, ultimately, peace negotiations.
Korea is industrialised slightly better than OTL Czechoslovakia, so expect a certain level of industrial capacity.
 
I just don't think you can defend with WWI/II technology.

You are fighting an industrial war with 2 massively larger and probably richer nations if it becomes a war of attrition you cant win without allies....

Well, for China the assumption was that they would either be divided as warlords or under a very weak and still mainly guerrilla units-based Communist Party. For Japan, well, the assumption was that it'd be similar to Fall Grun, the Nazi invasion of Czechoslovakia if the latter neither lost Sudetenland nor was willing to capitulate.
 
How different is your 1930s (what date?) countries from OTL? (in terms of Population and GDP etc)

A quick look gives me,
Population
Korea 21,058,300
Japan 64,450,005 (home island only, so more than 3 to 1 advantage by itself)
China 489,000,000 :)eek:)

Basically with 26 times as much population you are in big trouble in a WWI/WWII war unless you are much richer and better organized !
(I have not looked at DGP but unless you started with a very early POD Japan will be richer per capita due to earlier industrialization and will therefore only make the situation worse)

diplomatic/materiel support from the West or the USSR, will come eventually
With the IJN patrolling how do you hope for any supplies to get to you? (The Chinese army will cut the land route from USSR very early on)

I would suggest it will be much less than 180 day unless C&J are really badly lead and organized.
 
How different is your 1930s (what date?) countries from OTL? (in terms of Population and GDP etc)

A quick look gives me,
Population
Korea 21,058,300
Japan 64,450,005 (home island only, so more than 3 to 1 advantage by itself)
China 489,000,000 :)eek:)
Of course, it's very hard to try gauge number of trained troops by comparing gross populations, especially for East Asia - IOTL China had less than 50,000 fully-trained soldiers when the Japanese invaded Shanghai, and nominal army size was over 3 million or something. The rest were peasants without uniforms, weapons or training
Basically with 26 times as much population you are in big trouble in a WWI/WWII war unless you are much richer and better organized !
(I have not looked at DGP but unless you started with a very early POD Japan will be richer per capita due to earlier industrialization and will therefore only make the situation worse)
Expect Korea to have GDP per capita levels somewhere slightly above IOTL Japan's, around 3500$. A POD in 1876 has been used where Korea becomes a Republic early - mind you, I've been working on this for quite a while. You can find the TL in my sigged page under 'Twelve Republics'
With the IJN patrolling how do you hope for any supplies to get to you? (The Chinese army will cut the land route from USSR very early on)

I would suggest it will be much less than 180 day unless C&J are really badly lead and organized.
China's northeastern frontiers were traditionally very sparsely manned and defended. Russia has nothing to fear from the Chinese, not in the earlier decades of the 20th century.
Japan, of course, is a different animal. It will definitely try to cut the bottleneck that is the Russo-Korean border. Matter of fact, it might attempt a simultaneous attack on Siberian Russia and the Korean peninsula. While this means there will definitely be strong Russian cooperation, it does also mean Korea will be logistically isolated.
But, as said, I'm expecting this to work out similarly as the German plans for the invasion of Czechoslovakia, which OTL has proven would've been catastrophic simply due to the lack of experience soldiers had. Tanks were stopping by gas stations to refuel. Jesus! :p
 
Of course, it's very hard to try gauge number of trained troops by comparing gross populations, especially for East Asia - IOTL China had less than 50,000 fully-trained soldiers when the Japanese invaded Shanghai, and nominal army size was over 3 million or something. The rest were peasants without uniforms, weapons or training

Isn't that kind of assuming that China ITTL is still in the same situation as IOTL though? I mean, given Korea's situation is radically different so too might be China's.
 
Isn't that kind of assuming that China ITTL is still in the same situation as IOTL though? I mean, given Korea's situation is radically different so too might be China's.

Indeed, with such an early POD that might entirely be possible.
But for this specific scenario involving my Korea TL great effort will go into dividing up China, not even between warlords but also as different countries. Otherwise, if we are to assume China is a single entity with a very large and trained military, a defence plan may not even be worth it.
 

CalBear

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Can't be done. Zero possibility event.

The Koreans lack the industrial strength to outproduce either opponent (which BTW, is REALLY saying something), lack the money to buy weapons, and are so badly outnumbered that they can't put troops into the field in anything close to the number necessary . A multiple pronged invasion can't be stopped with the size force possible.

I will also say that there is ZERO chance, regardless of POD, that the Korean Peninsula is able to outproduce Japan in any non ASB 1910-40s. Simply not going to happen. They may manage to reach per capital GDP parity, but that still means the Japanese have an economy five times Korea's.

A well equipped force could make the enemy bleed, but even if all the Chinese supply are troops with spears they are going to flat overrun the defenders (who will literally run out of ammunition before they run out of targets). Throw in the IJA/IJN and you have an over match that starts to resemble the 1991 Gulf War.
 

Thanks for the response, really needed that.
How about asymmetric warfare? Would guerrilla warfare be successful in this case, say, than Poland or Yugoslavia?
(It'd definitely be relatively successful than direct warfare, as what you said proves - making the point of comparison moot)
 
How about asymmetric warfare? Would guerrilla warfare be successful in this case, say, than Poland or Yugoslavia?
I think that only works if J/C are busy with something else at the same time and regard Korea as peripheral and of secondary importance so not willing to deploy the numbers/ruthlessness necessary to win, not to mention that 'wining' a guerilla war tends to leave you in a bad state to do anything after....
 
I think that only works if J/C are busy with something else at the same time and regard Korea as peripheral and of secondary importance so not willing to deploy the numbers/ruthlessness necessary to win, not to mention that 'wining' a guerilla war tends to leave you in a bad state to do anything after....

That, or if the front moves too quickly. But I take your point.
What if only one country invades per scenario then - either China or Japan?
 
If you plan to use guerilla warfare, you should ensure that the partisans don't take over - happened last time and wasn't that good for the north.
 
Wouldn't it be possible that our hypothetical invaders from the Chinese direction might also possess significant naval and amphibious assets that could be used to outflank defense lines in the north or even open another front from the Japanese direction? What about the possibility of an amphibious invasions in the center region of the country, like Inchon in the Korean War.

(then we fuked bru)
Well, IMO it's assumable that this war plan was originally drawn when China was divided amongst warlords, and therefore has only basic naval capabilities. However, even in case of amphibious attacks the idea still remains the same: place submarine mines near all major ports, and fall behind second line of redoubt when the port cities fall.
(There's also the fact amphibious attacks are very hard to conduct in Inchon, or any city along the Yellow Sea for that matter - while high tides may have been overcomeable with Korean War-tech, this is most likely not possible with WWI-/Interwar technologies. This is my lack of naval knowledge speaking btw.)
 

CalBear

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Thanks for the response, really needed that.
How about asymmetric warfare? Would guerrilla warfare be successful in this case, say, than Poland or Yugoslavia?
(It'd definitely be relatively successful than direct warfare, as what you said proves - making the point of comparison moot)

Asymmetrical warfare only works if the enemy lets it work.

The Heer was too busy feeding troops into the Eastern Front meatgrinder to deal with the Partisans in Yugoslavia and the "Partisans" in the USSR were simply Red Army units with limited supply. Even then all those groups managed was to discomfort the Reich. If the Red Army had been defeated, how long would the Yugoslavian resistance have survived as a cohesive force?

The United States screwed around in Vietnam for 10 years, never even gave serious consideration to fighting a real war. If Washington had chosen to fight full out the PRC would have been looking over the border at element of the Big Red One instead of the NVA. Hanoi and Hai Phong would have resembled Berlin in January of 1945 and the Red River dikes would have been a memory. Not saying it would have been a good idea, but there wouldn't have been a whole lot of asymmetry involved.

The Soviets never really got serious in Afghanistan. The Soviet Army numbered 3,000,000 troops. Max deployment into Afghanistan was 115,000. It was a sideshow, and a poorly run one at that. The Soviets at least were smart enough to keep their costs down, especially compared to bumbling around that marked the U.S. effort in Vietnam.

Playing the low intensity card against the IJA would have been suicidal. This was an army that literally forced Chinese peasant women to toss their infants into the air so soldiers could spit them on their bayonets (documented in Nanking) and kidnapped THOUSANDS of civilian women for military brothels across Asia. They would simply have killed everyone in the village until the partisans had no one left to support them.

It is also worth remembering that every "successful" partisan campaign was supported materially by outside forces, be it the British support for the Yugoslavians, the overt Soviet support for the Vietnamese, and the CIA covert support to the Muj in Afghanistan. Eliminate that and those various movement will not disappear, but their effectiveness will drop off to nothing.
 
One thing that's worth flagging is that in China, where guerilla warfare was tried, the Japanese saw the Communists as annoyances in the rear, and saw Chiang's forces as their main enemy.
 
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