Notwithstanding the preeminence of Harry Hopkins during the last years of the Roosevelt administration, far-reaching changes were in the making. During World War II, Roosevelt accelerated one developing pattern, the bypassing of the secretary of state and his department, and established another, what the veteran diplomat Charles Yost considered "an even more unfortunate precedent…the persistent and intimate involvement of the military in foreign-policy decision making."
Another development of the Roosevelt years was the beginning of the growth of a large bureaucracy. However, since Roosevelt had an improvised and very personal administrative style, and there was no rationalization by statute, his personal assistants were scattered throughout the government. Truman introduced a significant degree of order, albeit with a large increase in the size of the White House staff. Moreover, under Truman the policymaking process was institutionalized through the creation of agencies responsible to the president. The National Security Act of 1947 created the Department of Defense and established the National Security Council (NSC) to serve as a top-level forum for thrashing out policy alternatives for the president's decision. An important corollary of the NSC was that it was provided with a staff, thus potentially giving the president his own mini Department of State.
Truman's belief in orderly administrative methods included a belief in a strong cabinet. He once said: "I propose to get Cabinet officers I can depend on and have them run their affairs," and as a result his White House staff was singularly weak. Secretaries of State George Marshall and Dean Acheson were the principal architects of Truman's foreign policy, with Defense Secretary James Forrestal at times playing a significant role. But the star of the Truman White House, Clark Clifford, made a mark because of the confidence Truman placed in him. Clifford generally reinforced with the president the views of such activist department officers as Acheson, Forrestal, and Undersecretary of State Robert Lovett, with one notable exception. In May l948, Truman followed Clifford's advice to recognize the new State of Israel over the objections of George Marshall and the Department of State.
As principal speechwriter, Clifford drafted the address enunciating the Truman Doctrine. George F. Kennan, then counselor of the United States embassy in Moscow, is usually credited with originating the doctrine of containment in his famous "long telegram" from Moscow, later published in Foreign Affairs under the title "The Sources of Soviet Conduct." Truman read the message and was impressed, but then he asked Clifford to prepare a memorandum on United States–Soviet relations. After talks with Marshall, Acheson, Forrestal, Lovett, and others, Clifford presented to Truman in September 1946 a memorandum differing from Kennan's chiefly in its military emphasis. "The language of military power is the only language which disciples of power politics understand," Clifford wrote. "The United States must use that language in order that Soviet leaders will realize that our government is determined to uphold the interests of its citizens and the rights of small nations." Kennan had stressed political and economic measures to contain Soviet expansionism and in later years, notably in his Memoirs, repeatedly deplored the military interpretation placed on his thesis.
Clifford resigned at the beginning of 1950 and later became a "distinguished outsider," advising Presidents John F. Kennedy and Lyndon B. Johnson, who in the last months of his presidency drafted him to be secretary of defense. Ironically, it was the man who had helped to militarize the American posture vis-à-vis the Soviet Union in 1946 who helped persuade President Johnson to end the bombing and seek a negotiated peace in Vietnam in 1968.