Bolder than Inchon: The Marines hit Nampo (Chinampo), North Korea, Sept 15th, 1950 - an operational comparison study

According to a Military Review magazine article, the three candidate points for
an amphibious descent on Korea for the UN forces at the end of summer 1950 were Inchon, Kunsan
(in southwest Korea, and the favorite of most observers) and Chinampo,
the port serving Pyongyang. Chinampo is most often annotated simply as "Nampo" on maps today.


The pros and cons of Chinampo have not been compared as directly as the Inchon versus Kunsan options. The historic debate between MacArthur and the JCS mainly fixated on Kunsan versus Inchon, but Inchon was what happened historically, and I'm not interested in discussing the ostensibly more cautious Kunsan alternative idea for now.

Let's say MacArthur is hot for going to Chinampo & exploiting into Pyongyang, instead of the historical one-two punch of landing in Inchon, and exploiting into Seoul. The Chinampo option really just quickly becomes his favorite, and he becomes dismissive of alternatives. He basically uses all the same historic arguments in favor of Inchon, the surprise factor, audacity, strategic-level dislocation of the enemy's rear, in arguing for Chinampo, and all the same as historical arguments against Kunsan (the North Koreans can pivot to react to and contain a landing in strength, possibly just leaving UN forces with a second Pusan perimeter, at best, helping push the North Koreans back on to their supply zone)

MacArthur gets ultimate deference at this stage as theater commander, but other military chiefs are prepared to say "I told you so." if it fails.

So, the landing is prepared for Korea's northwest coast. It is set for September 15th, coinciding, like OTL's Inchon offensive, with a build-up in the Pusan perimeter which actually more than matched the surrounding North Korean forces, and a UN counter-attack and break-out from the perimeter.

Is Chinampo successfully seized between September 15-September 19 by the US force that historically went to Inchon, matching the real-world Inchon schedule?

If not, why not?

Assuming the US forces are not extra tangled up in Chinampo, or repelled from the beaches, wharves, seawalls, etc., what happens next is just as important. Do the US-UN-ROK forces exploit inland in the weeks ahead to conquer Pyongyang, just in the real history, they exploited inland to liberate Seoul? In real history, US-UN-ROK forces liberated Seoul on September 28th, one day shy of two weeks after the Inchon landing of Sep 15th. [and incidentally, the 28th was 3 full weeks before the real world US-UN-ROK capture of Pyongyang on Oct. 19th].

If we treat all combat conditions between Chinampo and Pyongyang as roughly equal to those between Inchon and Seoul [which they would be, in terms of the invading UN force], and adjust for what we know to be different - basically Pyongyang is a bit further from the port, half again, or possibly twice as far as Seoul is, I think an extra week for the UN allies to take Pyongyang on October 5th is a fair rough estimate. This is admitting the unknown factors of differences in strength between available North Korean regular and paramilitary and militia forces and fixed fortifications in the Seoul versus Pyongyang areas, and the impact of a probably more acquiescent to North Korean regime civil population around Pyongyang, than around North Korean occupied Seoul.

But, in considering all this, not all factors may be equal in comparing odds of success between the Inchon-Seoul plan versus the Chinampo-Pyongyang plan:

Pro's Chinampo-Pyongyang compared to Inchon-Seoul:

- Hits North Korean political center of gravity
- Does more than any other options to decively cripple North Korean
sources of power
- Leaves US/UN forces with greater ability to catch any Pyongyang
regime officials fleeing into the hinterland
- Makes for a very non-permissive environment for deployment of PRC or
Soviet forces in northern Korea
- Cuts off NKPA ultimate sources of supply and command
- Inchon had nasty tides, tidal flats and seawalls. Maybe Chinampo's
an easier landing area (info gap), with fewer mobile forces streaming through.
-likely fewer mobile enemy forces streaming through, even harder for NKPA to
try to solve anything with a retrograde movement from battlefields deep in South Korea
-The Chinese are much less prepared to intervene at this point, they
are forced to decide to intervene, or hopefully not, earlier. If they rush an intervention, it is with a smaller force, less trained for this particular campaign, against UN forces that have not marched as far.

Con's of Chinampo-Pyongyang compared to Inchon-Seoul:

-The allied invasion armada and reconnaissance flights and naval sorties right before it require additional time to steam up further north into the gulf of Korea, where North Korea ground observers, aircraft and limited numbers of boats and fishermen who get debriefed are operating. Not sure how many additional hours compared with Inchon (6 to 12?) . There may be more chance for the North Koreans (or Chinese, or Soviet shipping/aircraft operating from Port Arthur or Dairen) to observe, report and relay an actionable tactical warning to North Korean defenders at Chinampo, compared with Inchon further south.
-North Korea, which once feared ROK invasion, may have better
prepared fixed fortifications, static garrison forces and solid
contingency plans for defending Chinampo and the capital prepared to
what it has improvised for the newly conquered Seoul-Inchon area
-It will take much longer to unite forces landing in Chinampo with
forces breaking out from Pusan, and it will take longer to liberate
South Korean population centers and to enlarge ROK forces and shove
them north to reinforce USMC and US Army, compared to OTL. There will be a slight time delay before the more mutually distant fronts begin to affect each other.
-The Chinese can still intervene in some strength, maybe it is enough
for their purposes against US/UN forces that are geographically harder
to reinforce.

Now, *if* the military operational success of a whole, multi-week US Chinampo-Pyongyang campaign ends up matching, basically, the success of the real-world Inchon-Seoul campaign, it seems to me this could "set" some advantages for the US-UN-ROK side that apply to a longer Korean war, relative to the real world Korean War, even if it does not preempt or prevent Chinese intervention entirely.

Even more of the historical North Korean early war army, officialdom, and possibly even some high-level political leadership has the potential to be "bagged" by Allied forces, even if Chinese forces intervene and push Allied forces back from the Yalu.

The Chinese, either intervening earlier, with less than historic strength and preparation, to keep up with the rapid Allied advance to Pyongyang and then the Yalu, and destruction of North Korean forces, or intervening at the historic time, with historic strength, but having allowed the UN-ROK position to consolidate more, should end up disadvantaged by this. While complacency should still let them push Allied forces back from the Chinese border itself, possibly even allow Chinese forces to seize Pyongyang for the Communist side, a weakened Chinese offensive is unlikely to prevent the Allies from regaining their compsure long enough that they are pushed south of the 38th parallel, or lose Seoul again. This should keep the South Koreans stronger and the North Koreans weaker for the whole war, and may motivate the Americans to aim for a ceasefire line well north of the 38th parallel, near Pyongyang, just north of it, or a little further north at the peninsular "waist", and make that goal achievable.
 
1 Chinese intervention and the massive soviet bloc's non lethal aid/lethal aid only became a possibility after the 29th of september 1950,

2 And only because douglas macarthur was a hot headed fire eating conflict/war fanatic and a fanatically anti socialist radical extremist with a raging media personality god complex as a loudmouth barking buffoon that loved being the center of media attention,

3 On 29th of september 1950 macarthur flew out to seoul to return the south korean capital to the government of syngman rhee and afterward's macarthur jokeingly said infront of war correspondent's that he was not going to stop at the yalu river but was going to continue all the way to nanjing to return the kuomintang,

4 The socialist chinese government was not laughing at this as they took the threat of a united nation's open invasion of china beyond deathly serious,

5 And it cleary did not help that even with india and the soviet union trying to broker peace deal's and china from the 1st of october openly makeing it's self clear by useing it's chinese embassie's in india and soviet union,

6 But both the united nation's and american's either dismist's out of hand or told them to politely censor off,

7 Had macarthur said nothing both china and the soviet bloc would have stayed out of the korean conflict even as united nation troop's dip their toes in the cold/close to freezing yalu river of a unified korea under syngman rhee,

8 But even if macarthur say's that joke and the landing's were at chinnampo chinese intervention was all about confronting united nation force's in the mountain's of north korea and stoping them there befor they can even get to and or across the border into china,

9 By fighting united nation force's to a stalemate in the mountain's of north korea long enough for india/soviet's/someone else to broker a peace deal,

10 With whatever is left of north korea as a mostly soviet/chinese controlled mountainou's buffer state between the soviet union/china on one side and south korea on the other side,
-------------------------------------------------
11 Or a unified korea as one of the neutral and non aligned third world countrie's like what austria/yugoslavia/finland and india had become by 1950,

12a That was the plan that the chinese had but five thing's that led to united nation force's expulsion from north korea were,

12b Victory disease,

12c Home by christmas disease,

12d Very heavy road dependency as united nation force's had forgotten all the 1940-1945 experience/knowledge of how to conduct mountain warfare and had to relearn it all over again in 1951-1953,

12e Yellow skin xenophobically gross disrespect of chinese military capabilitie's and leadership that lead to completely underestimating the chinese,

12f Gross negligence/gross recklessness/gross mismanagement of military operation's after the fall of pyongyang in the mad dash race to get to the chinese/soviet border's that set up the event's that led to great retreat from north korea in december,

13 Even with the chinnampo landing's most or all five of these thing's still have not been resolved.
 
Inchon landing was difficult enough, going even further North would increase difficulty. It's unlikely they would be able to do as efficient intelligence gathering as they did at Nampo, also Nampo is within estuary while Inchon is exposed, which means that marines would need to control much more ground to make the harbour secure, which would take more time and leave them with fewer forces for advance on Pyongyang.
 
Can't really see it impacting the OTL outcome that much. The forces that historically defended Seoul will be diverted to Pyongyang and it will be a tough fight but the outcome isn't in question. The breakout from Pusan did not require the landing at Inchon to suceed. Most likely Macarthur yeaces the Yalu and makes the same political errors as in OTL with the same results.
 

nbcman

Donor
I think that a major difference is Chinampo had a minefield protecting it but there were no mines (EDIT2: small quantity of contact mines laid, no magnetic mines) laid at Inchon. It took multiple weeks of sweeping in the approaches to and at Chinampo before ships began unloading after the UN forces captured Chinampo in mid-October 1950. The OLD SSI Korean war game Conflict: Korea had a mechanic for NK mining of harbors where the pre-war harbors had an increasing chance of being mined from the start of the war but the pre-war SK ports only had a chance for being mined after September. EDIT: That mechanic reflects the USSR started supplying mines to NK after the start of the war.
 
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going even further North would increase difficulty.
More "North-ness" in pure geographic terms, and no other factor does not seem by itself to add operational difficulty, The one inescapable operational difficulty of more "North-ness" to me seems to be additional time to get there, and more PRC maritime activity around those waters as I mentioned in the OP, leading to greater risk of the invasion force being detected and the defenders receiving a tactical warning. Which is nothing to sneeze at.

It's unlikely they would be able to do as efficient intelligence gathering as they did at Nampo
Yes - increases the risks of the unknown on D-Day itself, or the risk of intel gathering missions incurring casualties, or providing tip-off of intent to the enemy. All real things. If close surveillance, reconaissance is not happening, you may be relying on dated Japanese intelligence and surveys. With Inchon, you have first hand South Korean, embassy and attache reports only a couple months old, even before talking about recon missions.

also Nampo is within estuary while Inchon is exposed, which means that marines would need to control much more ground to make the harbour secure, which would take more time and leave them with fewer forces for advance on Pyongyang.
This also sounds like an important military geographic/operational factor.

a major difference is Chinampo had a minefield protecting it but there were no mines (EDIT2: small quantity of contact mines laid, no magnetic mines) laid at Inchon.
Important if true. I just don't know if the North Koreans were not *as rapid* about throwing out and deploying mines quickly in the newly occupied ports of South Korea. Would have been smart to do. But also totally makes sense for them to start the war with minefields at their domestic harbors, or deploy them within days of US naval participation.
 

nbcman

Donor
{snip}
Important if true. I just don't know if the North Koreans were not *as rapid* about throwing out and deploying mines quickly in the newly occupied ports of South Korea. Would have been smart to do. But also totally makes sense for them to start the war with minefields at their domestic harbors, or deploy them within days of US naval participation.
The North Koreans didn't start the war with minefields. But they started laying them once the Soviets started supplying them.
1709577860768.png

1709577949152.png

So at least a week before Operation Chromite there were numerous mines seen around Chinnampo by both the USN and RN.
 
More "North-ness" in pure geographic terms, and no other factor does not seem by itself to add operational difficulty,

It reduces the efficiency of air support and air supply. One of the key parts of operation Chromite was capture of the Kimpo airport, there is no comparable facility near Nampo, which means the landed force is only reliant on carrier support, which would be very problematic if they tried to march on Pyongyang.
 
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