Yet Vandenberg’s world is dead, and the policies that he and the brilliant Democrats around Harry Truman forged after World War II are less compelling than they were. A consequence of the midterm elections is that America’s commitment to free trade and the Atlantic alliance – the twin pillars of the postwar settlement – has been weakened. America and its European allies are having a bitter row over Bosnia, a matter that House speaker-in-waiting Newt Gingrich dismissed last week as ““largely a European problem’’ to which Americans should contribute neither blood nor treasure. Influential Senate Republicans, including Jesse Helms, soon to take Vandenberg’s chair, are openly contemptuous of Clinton and threaten to derail ratification of the GATT accord on expanding world trade. Is America abandoning its traditional leadership of the Western Alliance?

Not entirely. Congress will probably pass the GATT legislation. The president will go to Europe next month equipped with a blueprint for the new security architecture of Europe. ““For 50 years,’’ says Richard Holbrooke, assistant secretary of state for Europe, ““the U.S. has been the leading force in shaping the Euro-Atlantic security framework. President Clinton has made clear that we will continue to be so.’’ But instinctively, everyone knows that America’s commitment to the old tenets of internationalism is not what it once was.

Partly, this change is generational. Of the 435 men and women who will take their seats in the House of Representatives in January, 214 were first elected after the Berlin wall came down. For them, the cold war is history. With the collapse of the Soviet Union, the basis of the policies of the late 1940s has gone. Free trade was never wildly popular, but in the postwar years the United States had a virtually self-contained economy, so the policy could be piggybacked on the fight against communism as a bit of painless dogma. Now, in a populist political landscape, free trade is often feared as a source of economic insecurity.

Unsurprisingly, some Republicans are flirting with their party’s old attachment to protectionism. Some, indeed, never deserted that mistress: Helms, from the textile state of North Carolina, is one of them. Now many younger Republicans, tinged with Perotist populism, are similarly tempted by protectionism’s charms. ““Nationalist’’ Republicans, meanwhile, have attacked the new World Trade Organization, which, with strong enforcement powers (long an American demand), will replace the GATT next year. Those sus-picious of the WTO – including Bob Dole, soon to be Senate majority leader – claim it could give banana republics the power to void American laws.

True, Dole’s opposition to the WTO will probably be bought off. But it isn’t just on trade that the legacy of the 1940s is under attack: so is the Atlantic alliance. Dole has consistently argued that the arms embargo on Bosnia should be lifted, and this month, under congressional pressure, the administration ceased to enforce it. This risks a rupture with the European powers. The French and British believe that if more arms flow to Bosnia, their peacekeeping troops will be caught in the cross-fire. European concerns have been heightened by news that, at Congress’s request, the Americans are considering a $5 billion package of military aid to the Bosnian government.

In Paris, America’s actions on Bosnia are proof that it is disengaging from Europe. In London, the government hopes that that is not true. And on both sides of the Atlantic, there is a fear that Bosnia will poison next month’s discussion on European security. In Brussels and Budapest, Washington will propose ways to extend NATO’s security perimeter eastward so as to minimize Russian fears. Yet even if agreement can be found within the alliance on the ““why’’ and ““how’’ of NATO expansion – not certain – Senate endorsement of such a move is uncertain.

There are still plenty of staunch GOP internationalists in the Senate. But the president is weak and unpopular, and America’s mood is inward-looking. The prospect of Republicans deciding to treat the borders of Slovakia, say, as if they were those of South Carolina (and that’s what ““NATO expansion’’ means), remains misty. In the uncertainty over trade and European policies, the shape of a new international order can be dimly perceived. But it’s not one that Arthur Vandenberg would recognize.