The version you heard growing up is the one that's been traditionally taught about the Korean War for decades now. It's certainly the version represented in most of the literature on the subject up until the 21st Century.

The issue pivots on Stalin's letter of August 27th to the Czech President Gottwald which more or less lays out the notion that the Soviet absence from the Sec Council meeting was a deliberate diplomatic trap laid for the Americans.

As with many documents from inside Stalin's government, there's a paucity of conflicting or corroborating views in the literature.

The Truth? The truth is we don't know. We know the USSR was absent from the vote and that this allowed the US to get the UN on board with intervention. We know Stalin claimed that it was all part of a master plan in his letter to Gottwald.

But what we don't have evidence for one way or the other, to my knowledge, is someone inside Stalin's inner circle planning out this series of diplomatic moves in advance.

The Soviet Government was prone to ret-coning things, an effort that famously extended even to photographs of individuals with prominent party officials. See, by way of example, the removal of Yezhov from photos with Stalin taken in the 1930s - before and after.

So the question really is, do we trust the Soviet narrative on this issue? Was Stalin simply writing to reassure an ally an altering the story to suit his purposes or was the international community really the victim of a diplomatic double fake worthy of Bismarck?

Without more sources we can't know. By the time Stalin wrote this letter the UN had already established a foothold in Korea and, until the Chinese became involved in the conflict in November (at Stalin's direction) things were looking very grim for North Korea, at least strategically speaking. Depending on your view of the importance of air-power the North Koreans may have been in a superior tactical position but that's another issue for another thread.

Now the letter in question got its first real brush with academic history in the 2005 publication Novaya I Noveishaya Istoriia by Donggil Kim and William Stueck of the Beijing University and the University of Georgia (not the one in Tbilisi). Kim puts forth the second narrative you're encountering and Stueck offers a counterpoint to it.

The Wilson Center has a pretty good treatment of the letter and the point-counterpoint between Kim and Stueck which you can find here.

There are a number of sources on Soviet historical negationism and I'd encourage you to seek them out but, as you do so, please remember that the boundary between "history" and "current events" is fairly thin when it comes to the cold war and, in particular, to the study of its history. Many of the authors who have written on this subject have a political agenda and disentangling that from their scholarship is difficult. Out of respect for their work and in recognition of what are surely political biases of my own (to which I am no doubt blind) I will refrain from naming names and urge you to read critically and draw your own conclusions.

/u/pm-me-ur-window-view

Repost a previous answer

In 1950 as the Korean War broke out with North Korea's invasion, the USSR was boycotting the UN Security Council since January of that year, due to the refusal of other members of the Council to seat the PRC instead of the ROC. Ironically, this boycott meant the USSR was not able to cast its opposition to UN resolutions condemning North Korea's invasion when the Security Council met on this issue in June 1950. There was some real fear that the PRC would use the resulting chaos and panic to invade Taiwan, thus Truman ordered the US Seventh Fleet to patrol the Taiwan Strait.

At this stage of the Korean War, the PRC maintained an ambivalent stance. It blamed South Korea for being aggressive towards North Korea yet it downplayed the magnitude of the war itself. It remained neutral and made little of North Korea's early gains. Its press expressed concern that US military movements into South Korea was a regional threat, yet it moved some of its troops in Fujian -- troops that had been there with the intention to attack across the strait into Taiwan -- to the northern regions both in recognition that they could not invade Taiwan with US presence nearby and also to downplay their threat to Taiwan.

In early August 1950, when the situation looked grim in the last stand of South Korea and US troops in the Pusan Perimeter, the UN facilitated talks with the PRC to raise the prospect of PRC membership on the Security Council if the PRC will help mediate the conflict. So, there was already some acceptance that the PRC should have the seat on the Security Council, in particular due to the declining power of the ROC itself.

However, at the same time the supreme commander of Allied forces commander of UN forces in Korea Gen. Douglas MacArthur held his own meetings with Chiang Kai-shek in which he declared Taiwan to be an integral part of US defense and security chain in East Asia. More strongly, Chiang offered the deployment of ROC troops in Korea, but this was turned down. Regardless, all this turned the UN negotiations with the PRC hopeless, as the Korean War and the issue of PRC-ROC was turning into one political conflict.

By late August 1950, the US Congress approved emergency measures and funds, and the US/South Korea forces started to beat back the North Koreans. This turned the PRC rhetoric from ambivalence to outright aggression. The eventual PRC entry in the Korean War turned its relationship with the US into enmity until the late 1960s, during which time the two had limited diplomatic contact. In addition, internal challenges in the PRC due to the Cultural Revolution made improving relationships difficult.

But toward the 1970s, the PRC started to be concerned with its own relationship with the USSR. Criticisms between Mao and Krushchev, in addition to unresolved border issues that spilled into popular arguments, led to deployment of troops that culminated in armed conflict. Finally, rejection of USSR expertise and internal economic crises meant the PRC was becoming dependent on its oilfield production, which was in serious decline. China has always been an oil importer, but discovery of new oilfields in the 1960s fueled speculation that it may become a major exporter if expertise and investments were made available. In the worst times, the oilfield industry was the only growth industry in the PRC.

Thus, PRC leadership started to change their rhetoric in the 1970s, and started to broadcast their willingness to communicate directly with the US. The US, of course, was interested in taking advantage of the Sino-Soviet split and wanted to gain access to China. By this point, most other countries had moved to support the PRC's wish to be a member of the UN and have a seat on the Security Council, with the US being the notable major power opposing this. Thus, US support of a change in policy, under Nixon, removed nearly the last hurdle.

At this point, discussion of what was to happen to the ROC came about. Both the ROC and the PRC was strongly insisting on the One China vision, thus a compromise became impossible. The US attempted to push a procedural vote to allow both the ROC and the PRC to have seats on the Security Council, but this was narrowly rejected. Thus, the resolution giving the seat to the PRC specified strongly that it was a “restoration of the lawful rights” to the PRC. This suggests that the PRC should have been given the seat in 1949.

• Spence, The Search for Modern China, 1990.

• Meidan, The Structure of China's oil industry: past trends and future prospects, OIES Paper WPM 66, Oxford Energy Institute, May 2016.