He served four and a half years as one of four Assistant Secretaries, nearly all the time under Cordell Hull, the longest-serving but not the most influential Secretary of State (for Roosevelt encouraged him to concentrate on trade policy not high politics), and then under Edward Stettinius whose distinction of appearance many people, including Acheson, regarded as about ten times that of his mind. The shunting of Hull away from the political mainline suited his Assistant Secretary for Economic Affairs quite well, and Acheson was able to play an effective role in negotiating Lend-Lease and the Bretton Woods currency agreement. In both cases he enjoyed having Keynes, ten years his senior, as an interlocutor. Keynes sometimes offended Americans by his impatient intellectual speed, and Acheson sometimes offended his own countrymen and others by his inability to suffer fools gladly. But in this relationship neither wanted to or could patronize the other, and they got along well, with the distinct but not excessive superiority of Keynes’s mind balanced by the superiority of the national power which was behind Acheson.
In the summer of 1945 Acheson thought the time had come to resume his lucrative private practice of the 1920s and 1930s. The war against Germany was won, and that against Japan was unexpectedly on the brink of following. Roosevelt was dead and Truman was President. First Hull and then Stettinius had resigned. James F. Byrnes, who had the fatal flaw for a Secretary of State of thinking that he and not the incumbent ought to be President, had taken over the State Department. Acheson achieved a week of freedom from office in early August and was then summoned back to become Under-Secretary, that is, number two man as opposed to one of four number three men in the Department. He held this office for twenty-two months until January 1947, and achieved almost as much in it as he was subsequently to do in his four years in full charge of the State Department. Byrnes spent a great deal of time abroad. This was partly because of the leisurely rhythm of mid-century diplomacy. Bevin did the same, sometimes being away from London for six weeks at a time, as was Byrnes from Washington. But it was also because Byrnes did not respect Truman and Truman did not trust Byrnes. They were like a husband and wife who could keep going only if they did not often coincide in the same house. As a result Acheson came increasingly to be both the co-ordinator of US foreign policy in Washington and the man who kept the White House and the State Department, then only a couple of hundred yards from each other, within hailing distance.
The Truman-Acheson relationship was at once bizarre and crucially beneficial for the Western world. They were utterly unlike each other, yet became locked in an alliance of mutual respect and affection. The key date was 6 November 1946. Nineteen forty-six was the nadir of Truman’s presidency, although the first half of 1948 and even 1952 with its end-of-regime wave of petty scandals were both pretty bad. Although Truman’s reputation has stood so high for the past twenty-five years, he enjoyed no similar esteem when he was actually doing the job. At all three periods his poll ratings were abysmal. But by early 1948 he had gained confidence and a sense of direction, and in 1952 he knew that he had steered the country through seven testing years. In 1946 he was unproven and floundering. There were quite serious suggestions that he ought to resign the Presidency. He took no notice of them but he did accept the humiliating advice that he should play no part in the mid-term congressional elections. The only hope for the Democratic candidates, it was suggested, was that the Democratic President should neither open his mouth nor show his face.
He insisted on going home to vote in Missouri, but his journey across half the continent in the presidential train was conducted in silence and almost in solitude. There were no whistle-stop speeches. On the way back he was informed of the results, the disastrous nature of which had not been avoided by his abstinence. The Democrats had lost control of both houses for the first time since 1928. At union Station, Washington, there was no one to meet the President except for the unmistakable figure of Dean Acheson, solitary and distinguished, who had gone there of his own volition, way beyond the duties of his office, partly because the disdain which made him suffer fools so badly also made him perversely loyal to those who were down. When the Alger Hiss security scandal broke three years later Acheson pretended that he had known Hiss much better than was the case. (It was Hiss’s brother with whom he had worked closely.)
Acheson’s 1946 presence on that railroad platform also became symbolic of the transition from the first to the middle phase of the Truman presidency. At first Truman felt at home only with Missouri cronies and with very political politicians. At the time of the Chicago convention which had nominated him as Vice-President he would have been amazed to be told that he would rather have been greeted by the acerbic Acheson than by the manipulating Byrnes, still Acheson’s nominal superior, although soon to be eased out. Yet such was the case. Truman took Acheson back for an assuaging gossip at the White House and thereafter a special bond existed between them. Two months later General George Marshall returned to Washington from his long mission to China and immediately replaced Byrnes as Secretary of State. Acheson and Marshall were as different from each other as they both were from Truman, but they together constituted the twin and essential props for the creative international success of Truman’s presidency. Yet they did not do it like crutches supporting a lame man. Their regard for Truman was just as high as was Truman’s for them. They constructed a tripod of American leadership which shaped the Western world of the next forty years and, despite the hazards of the cold war, gave it unprecedented prosperity and unusually long-lasting peace.