Douglas MacArthur was initially supportive of the policy of containment in Korea, as he believed it was necessary to prevent the spread of communism in East Asia. However, as the Korean War progressed, MacArthur became increasingly frustrated with the restrictions placed on his command by President Harry Truman and the Joint Chiefs of Staff. He believed that he should be allowed to pursue a more aggressive strategy, including crossing the 38th parallel into North Korea, in order to achieve victory. Truman and the Joint Chiefs disagreed, fearing that such a move would lead to a wider war with China. The disagreement between MacArthur and the Truman administration over the conduct of the Korean War ultimately led to MacArthur's dismissal from command in April 1951.