The most complicated problem faced by Chinese policymakers in its decision on entering the war involved its relations with its ally, the Soviet Union. Unlike America, China was not a leader of the socialist camp and not a power powerful enough in military and economic terms to fight America all by itself. It had played no role in diplomacy about the peninsula and did not carry great influence. Recently declassified files show that around the time when the Korean War broke out Stalin assigned a role of limited participation to China. It was not until three days after the breakout of the war that North Korea notified China of had happened.

China’s decision to enter the war was not made on the request of its ally the Soviet Union, but the decision always hinged on its relations with the Soviet Union. Their consultations centered on two questions: whether China would enter the war and what commitments the Soviet Union should made if China entered the war. The first question was further complicated by disagreement among the Chinese leaders. Stalin obviously would like China to dispatch troops to Korea and seized every opportunity to exert his influence on Chinese leadership. In light of the different roles the two countries played in the socialist camp at that time Stalin’s influence should not be underestimated. Mao Zedong immediately decided to send troops to Korea after receiving, almost simultaneously, suggestions from Kim Il-sung and Stalin. In the telegram to Stalin he drafted on 2 October, Mao Zedong elaborated in detail his estimate of the war prospect and the difficulties China was faced with.[7] Since he could not win the majority to his side Mao Zedong did not send out the telegram. He informed the Soviet ambassador to China of the opposition among the leadership, including the fear that “direct conflict between China and America” would undermine the plans for China’s economic reconstruction which had already begun and spark the dissatisfaction of China’s various sections of people.[8]

In a telegram to Mao Zedong probably on 5 October, Stalin claimed the Americans were not ready for a large-scale war and promised if America spread the war to China the Soviet Union would fight side to side with China. He specifically pointed out that China’s entry into the war would force America to yield and give up Taiwan. On the contrary, if China did not enter the war, it would not be able to have Taiwan.”[9] At about the same time when the above telegram was sent, the CPC Central Committee made the decision to send troops to Korea.[10] But Mao Zedong still felt it was necessary to further coordinate China’s policies with the Soviet Union, so he told Stalin China would “not send its troop just now” and would like to send a delegation to Moscow for consultations in detail.[11]

After China made the decision to enter the war the policy coordination between China and the USSR pivoted on the Soviet commitments to the war, including whether Moscow would provide assistance as Chins requested and what was the bottom line for China’s entry into the war if Moscow failed to fully satisfy China’s demands. Mao Zedong insisted from the very beginning that the two countries coordinate their actions and it was necessary for the Soviet Union to offer aid to China.[12] on 8 October, the same day when the CPC Military Commission issued “The Directive for Creating the Chinese People’s Volunteers,” Zhou Enlai and Lin Biao left Beijing for Moscow. Zhou Enlai’s talks with Stalin centered on whether China would enter the war and if China entered the war what assistance the USSR would provide. During the negotiations China made tremendous efforts in coordinating its policy with its ally and paid high costs. But these efforts and costs were worth it: China’s strategic interests were ensured and the Americans had to deal with two big powers acting in close coordination.

II.      Decision to Cross the 38^th Parallel

On 27 September 1950 the U.S. administration empowered Douglas MacArthur to drive his forces across the 38^th parallel and take the whole of Korea by force, which finally led to China’s entry into the war. The CPVs launched the third campaign on 31 December 1950 with the aim to annihilate the main force of the enemy between the 38^th and the 37^th parallel and lay a foundation to force the American troops to withdraw form the Korean Peninsula. At the end of the campaign the Chinese and Korean forces crossed the 38^th parallel and approached the 37^th parallel. A comparative study of the deliberation of relevant factors in the decision making to cross the 38^th parallel on the two sides is of special significance for research on local war between big powers. We could see how easily the policymakers were carried away by the military victories at a particular phase and change their already made strategic decision.

1.  The American decision to cross the 38^th parallel

The initial goal of American intervention was limited to the restoration of the situation in the Korean Peninsula to the state of 25 June 1950.[13] The fear lingered in the mind of American decision-makers that military intervention might trigger a total confrontation with the Soviet and invite their surprise attacks in other areas, especially in Europe. By late July, with the situation on the Korean battlefield becoming relatively stabilized, the competent departments began to consider revising the objective of intervention. By early August little voice was heard in the U.S. administration objecting crossing the 38^th parallel. From late August to early September the American government successively made decisions to cross the 38^th parallel, that is, the goal of American intervention should be the occupation of the whole peninsula under the condition that China and the Soviet Union would not directly join the war.

MacArthur started the landing operation at Inchon on 15 September and the following day the American Eighth Army at Pusan launched a counteroffensive. The unexpected military victories induced Washington to make a quick decision to go beyond the 38^th parallel. The Joint Chiefs of Staff gave MacArthur the power “to attack and wipe out the armed forces of North Korea.”[14]

The key factor for the American decision for northward advance lied in the American authorities’ exclusion of a possible Soviet and Chinese direct intervention. With the development of the war situation the American leaders were more and more convinced that the possibility of a direct Soviet involvement was becoming increasingly slimmer. When they decided to cross the line they were quite certain of no Soviet intervention although all the directives stipulated emergency measures in case of Soviet interposition. China’s reaction was another question America was concerned about. From late August, with American forces getting closer and closer to the 39^th parallel, the Chinese government began to issue strong warnings and explicitly stated that if the U.S. troops really crossed the 38^th parallel it would not sit by idly and remain indifferent. Early in the morning of 3 October Zhou Enlai urgently summoned Indian Ambassador to China K.M. Panikkar to an interview and issued a clear warning to America through India. But the American leadership treated Zhou Enlai’s warning as “blackmail” and “intimidation.”[15] The U.S. troops crossed the 38^th parallel in force on 7 October. The Joint Chiefs of Staff authorized MacArthur on 9 October to seize the whole of Korea if he was sure of success.[16] This decision brought a disaster to the American troops.

Another important reason for American failure in Korea was over reliance on its battlefield commander MacArthur’s own decision, which aggravated the mistakes of the American leadership in their macroscopic guidance of the war.