No chinese intervention during korean war

[Hendryk]

I'm don't know how close relations between the US and Taiwan were at the time so you could well be right.

The US didn't have relations with "Taiwan", but with Chiang Kai-shek's Nationalist government, and they were at an all-time low. The Truman administration had decided back in 1947, when the civil war between the Communists and the Nationalists had resumed in earnest, to leave Chiang to his own devices. By 1949, following a major strategic mistake by Chiang the previous year, the Communists were sweeping south from their Manchurian stronghold and pushing the KMT's forces ever further back until most of mainland China had been taken over and Chiang's government had relocated to Taiwan.

In fact, contrary to what I wrote earlier, the US decision to include Taiwan in its strategic sphere was made before the Chinese intervention in Korea began, so my point is moot. This is from Globalsecurity.org:

On 05 January 1950 President Harry Truman announced that "the United States will not involve in the dispute of Taiwan Strait", which meant America would not intervene if the Chinese communists were to attack Taiwan. However, on 25 June 1950 the Korean War broke out, and President Truman reacted by declaring the "neutralization of the Straits of Formosa" on June 27. The Seventh Fleet was sent into the Straits under orders to prevent any attack on the island, and also prevent the Kuomintang forces to attack on China. From that point on, Taiwan was placed under US military protection.

So by the time China intervened in the Korean War on October 25, 1950, Taiwan was already considered off-limits to Communist expansion.