The US Sectary of State, Dean Acheson, considered the events of 1949 to have changed everything, forcing the Truman Administration to review both the goals and tactics of American policy towards the Soviet Union. The NSC 68 exemplified the consistent objectives of US diplomacy, from contrasting Communism with Democracy in areas that were viewed as swing nations, the gradual erosion of Soviet influence and power within the Soviet sphere, to, ultimately, the collapse of the Soviet system itself. Ernest R. May argues that the NSC 68 provided the blueprint for the (American) militarization of the Cold War. The document stemmed from the concept of containment, which was first developed by George F. Kennan in 1947. This concept highlights the importance of containing the geopolitical expansion of the USSR and argued that a policy of containment was imperative. Members of the NSC, such as Kennan believed the Soviet aim was to develop a buffer zone purely to bolster its security. However, Chairman Paul H. Nitze contended that It is quite clear from Soviet theory and practice that the Kremlin seeks to bring the free world under its dominion by the methods of the cold war. Thus, May argues, Nitze prioritised the rollback of Communist expansion, leading the NSC 68 to potentially discard alternative policies of dÃ©tente and containment of the Soviet Union. Subsequently, when 75,000 North Korean troops crossed the Parallel, the American response was purely to prevent the spread of communism.
However, there is an alternate hypothesis, suggesting that Truman had an ulterior motive for his intervention in Korea, which was to expand America's influence in East Asia. Ambrose argues Truman had several aims in 1950: to extend containment in Asia; to support Chiang; to retain US bases in Japan and to rearm the US and NATO. As previously mentioned, the Truman administration agreed that Connolly's chain of defence in the Far East was an absolute necessity. Acheson stated in his Press Club Speech that maintaining their military position in Japan was required, both in the interest of our security and in the interests of the security of the entire pacific area. In Japan the US were orchestrating a peace treaty, but after a series of violent demonstrations organised by the Japanese Communist Party, Japan was less inclined to agree this. Thus, Truman needed an excuse to maintain the bases in Japan. Ambrose argues Truman and Acheson were under intense pressure to resume funding to Chiang. In a radio address, Robert A. Taft claimed Truman was willing to turn China over to the Communists, in order to see the downfall of nationalist China. Robert J. McMahon argues that Acheson considered it foolish to continue throwing away military aid on a lost cause. At a time where the Red Scare and McCarthyism was at its height, this was perceived as the Democrats going soft on communism. Therefore, due to the domestic political pressure, Truman felt he had to prove to Republicans and the general population, that he would stand firmly against communism. Ambrose's thesis is that the aims of the NSC 68 and Truman's agenda could be wrapped up and tied with a ribbon by an Asian crisis. Therefore, Truman needed another crisis. On the 25th June 1950 these needs were met.
Within an hour, Truman had already made the decision to intervene in the events in the Far East and was ready with countermeasures. In the hours that followed he instructed General McArthur to send supplies to South Korea; sent the U.S. Seventh Fleet to the Formosa strait, to prevent any attack against Chiang; and pledged additional assistance to the French against Ho Chi Minh in Indochina and to those fighting the Huks, in the Philippine Insurgence. An emergency United Nations Security Council (UNSC) meeting was called, in which they approved a US sponsored resolution, labelling the DPRK as the aggressors. This was the first time an international body had taken concrete steps to halt and punish aggression. Gaddis argues that the US troops already stationed in Japan and Stalin's boycott of the UNSC meetings, allowed Truman to intervene with little difficulty. Ambrose observes how, despite UN involvement supposedly leading the defence for Korea, the bulk of the equipment and Non-Korean troops were American. On the 27th June Truman publicly announced that the Truman Doctrine had officially been extended to Asia, outlining the US's involvement in Indochina, the Philippines, China and Korea. Since 1941 America had a policy of avoiding US ground troops on mainland Asia. Ambrose states that Truman believed under advice from Air Force Military planners, a bombing campaign alone would be sufficient to restore peace and border; the arms provided and financial support to the French would be enough to quash Ho Chi Minh and the Seventh Fleet could save Chiang. Ambrose describes this as wishful thinking, founded from the racist attitude that Asians could not stand up to western guns. But by this point Truman had already committed himself to the Far Eastern Problems.By August, Truman had successfully obtained from congress a $12 billion military budget for American action in Korea. By the end of the Korean War over 1,789,000 American troops had served in Korea, this was 31% of the active troops the US had worldwide from 1950-53; all evidencing the measures Truman took to involve himself in East Asia.
Korea was a mere piece in Truman's jigsaw of solving the wider Asian question. His aims clearly aligned with those set out in the NSC 68; Korea was the perfect opportunity to address domestic pressures, maintaining a chain of defence, containing communism and appeasing the NSC. Moreover, the obscene amount of American input in Korea, compared to the contributions of everyone else within the UN and the RPK, evidently demonstrated Truman's role in the outbreak. These factors drove America to a higher level of intervention in their support of Rhee, which in turn, transformed a localised skirmish into the first proxy conflict in the Cold War.
The extent of Stalin's responsibility for the Korean War continues to be debated and reinterpreted by historians. The debate around whether the internal Korean influences were responsible for the outbreak of the conflict contains some merit. Syngman Rhee's unpopularity and incompetence had forced him onto a trajectory heading straight for a collapse within his own government; Kim was impatient and wanted to send his army to conquer South Korea, this combination left tensions rising dangerously high within Korea and it became inevitable that an attempt at reunification, whether political or military, would occur. However, without the American military support and UN's backing, the PRK had not the military strength to adequately defend itself. This potentially meant only an invasion of South Korea could take place, as the PRK would not have the arms nor manpower to engage in a war. Stephen Ambrose raises many valid questions of the nature of the relationship between the US and PRK and the US's intentions. Odd Arne Westad's develops this view with his claim that Washington and Moscow wanted to exploit the Korean developments, to further their own interests or thwart those of their adversaries. Together, these perspectives capture the essence of the argument, that both Stalin and Truman held some level of contempt for the people of Korea, using their Nation as a pawn on the board of Eastern Asia. Truman needed an Asian crisis, finding the Korean tensions convenient for fulfilling his agenda: responding to domestic concerns over the Democrats response to China, and thus their outlook towards Communism; maintaining the defensive perimeter; expanding the Truman Doctrine to East Asia; and satisfying the goals set out in the NSC 68. Furthermore, the effort Truman went to, to ensure that a UN resolution was pushed through the UNSC, labelling the DPRK as the aggressors, demonstrated Truman's intentional desire for a proxy war. Nonetheless, Stalin's intentions for joining the war effort, in order to create a buffer zone, led Stalin to enable Kim to initiate a war effort against the South.
Both Truman and Stalin wanted to maintain and expand their ideological influence, in order to create some sort of defensive security zone. Their failure to unify Korea in a post WWII effort, and their subsequent establishment of the 38th Parallel, ignited the internal Korean factor. Stalin's endeavours to provide Kim with all the financial and arms provisions Kim felt necessary, in order to invade RPK, demonstrated Stalin's desire for a Korean conflict. Ultimately, Stalin enabled Kim-Il-Sung to invade the DPRK, but it was Truman who was responsible for escalating a localised conflict into the Korean War.