Clinton is serious about the 1940s. At least, he is serious about reading about them. He has been taking a look at the chapter in David McCullough’s s recent biography of Harry Truman on the making of the Truman Doctrine-and intends to use his speech to the United Nations on Sept. 27 to set out an “American Doctrine.” He has to say something. Although representatives of Israel and the Palestine Liberation Organization were to come to Washington to sign their agreement on Monday, the breakthrough came during talks to which the United States was not a party. True, America’s contribution to the process has not been insignificant: without the debates in the American-sponsored formal peace talks, the decisions in the informal talks between Israel and the PLO might not have been made. Still, Clinton’s comments revealed a need to assert that America was engaged in the diplomacy of the post-cold-war world.

The president had to take such a line because of the perception, in foreign capitals as in Washington, that he is nervous, anxious, when forced to consider foreign policy. Like a child reciting an old poem, he can speak the words without knowing quite what they mean.

It will take more than a South Lawn signing ceremony, complete with certain plaudits for Clinton’s role, to remove doubts about his administration’s competence in foreign policy. His critics will remember the endless round of agonizing on Bosnia, the tough talk in a climate when neither public opinion nor American allies would countenance tough action. They will note the way America has slipped ever deeper into the mire of Somalia, leading, last week, to action by American troops in Mogadishu that left scores dead. They will grumble that some in the administration seem less than keen on a freetrade agreement with Mexico.

The problem, since Clinton has brought the matter up, is that comparison with the late 1940s. At first sight, this nostalgia at the end of the cold war for the years at its beginning seems unwise. America in 1945 was economically unchallenged, accounting for roughly half of the world’s economy, about twice the share it has now. That bred a confidence at home, now missing, that provided the essential underpinning for an activist policy abroad. And the giants who made America’s postwar foreign policy had one advantage denied to Clinton-the existence of an opponent in the Soviet Union whose interests and movements they could use to calibrate their own.

Still, even given such advantages, America’s postwar foreign-policy principles were clear. They went beyond the now redundant (with luck) need to contain the Soviet Union. They extended to a commitment to rebuild the economies of Europe through the Marshall Plan and to encourage international financial stability and an open trading system, not just for the fun of it but because these things were in America’s interests.

The Marshall Plan cannot be duplicated. But perhaps something can be learned from the 1940s, after all. The first lesson is to get priorities straight. The men of the 1940s concentrated on Europe. That was where America’s expertise seemed most developed, where its economic interests lay–and expertise plus interests equals influence. If America has interests and expertise in Somalia, by contrast, they seem remarkably well hidden; Bob Dole, the Senate minority leader, has said candidly that at this time America has “no clear interest at stake” in Somalia.

The Middle East, however, is a region in which there is both longstanding American diplomatic expertise and clear American interests–interests in the preservation of an unfettered supply of oil and in the security of Israel. Clinton now has a chance to show that he can use America’s influence in the region to good effect: to help broker agreements between Israel and its other Arab adversaries; to provide some security guarantee to the whole area; to take the lead in a program of economic assistance to Gaza and the West Bank. Failure in Somalia, even in Bosnia, need not be a fatal blow to America’s reputation in the world. But if Clinton looks unconvincing–or worse, irrelevant–on the familiar ground of the middle East, we will know that, in foreign policy, he is not up to the job. Those who take Harry Truman as a model set themselves high standards.