For proof, consider not three, but four recent examples. Powerful lobbies in Washington could yet prevent the country signing - and thus destroy - the planned global climate treaty that would lower pollution emissions. Last month, American opposition may have consigned an international agree- ment to ban land-mines to a similar fate. Blending dollops of self-righteousness with pleas of impotence in the face of Congressional opposition, the US balks endlessly at paying its dues to the United Nations. Now it is in another minority of one, trying to extend the reach of its national laws to prevent the sovereign states of France, Russia and Malaysia signing a gas development deal with Iran.
Now, on each individual count apologists can mount a more or less plausible defence. After all, was not the European Commission at least as "extraterritorial" when it demanded - and secured - changes in the merger between Boeing and McDonnell-Douglas, which surely was none of its business? Then again, is not an exemption justified for its mines guarding South Korea's borders with the North, arguably the most dangerous frontier on earth? Maybe industrial gases aren't responsible for global warming. And few would dispute America's complaints about bureaucracy and incompetence at the UN. Cumulatively, however, one overwhelming impression remains: "Washington to Planet Earth: Get Lost."
In a sense of course, the sentiment is not entirely new. Famously, the opposite polar forces behind American foreign policy are idealism and isolationism, the alternating convictions that America must either mend the world, or stay out of it. Both flow from the doctrine of American "exceptionalism", that it is a country unique in origin and conceived by God for a special moral, and moralising, purpose.
These days, moreover, the exceptionalism embraces economics, and the unqualified triumph, in US eyes at least, of the American model of hard- nosed free-market capitalism, so messianically and maddeningly proclaimed by President Clinton to his fellow heads of government at the recent G- 7 summit in Denver. Strong growth, low inflation, high employment, innovative dynamism, US officials brag: you name it, we've got it. The dollar is strong and the Asian tigers have been de-fanged. And what's that fuss in Europe about budget deficits of 3 per cent? We're heading for a budget surplus in 1998. American exceptionalism? More like American arrogance.
If so, however, it is an arrogance born of weakness - not of the country's position in the world outside, but of its internal political system. Some of the frictions are inevitable. Led by America, the West won the Cold War - but that victory removed the overarching reason for Western solidarity. Once the ultimate guarantee of Europe's obeisance to its patron superpower, the American nuclear umbrella is no longer of paramount importance. But the true problem lies within.
Today there is no such thing as a coherent American foreign policy, rather an abject series of gestures to various interest groups. This is not to demand what George Bush once plaintively called "the vision thing", a strategic concept of world affairs, of Kissingerian sweep. But it does require an end to a policy of pandering, and Mr Clinton's reflex of acting to please the immediate audience. He may plead the problems of divided government, a Democratic White House in intermittent but inevitable dis- agreement with a Republican Congress. That does not excuse him from demonstrating at least some willingness to take on vested interests, be they the Pentagon in the case of land-mines, the oil and energy industries over emissions, Republican obdurates over the UN, and the Jewish lobby and sundry seekers of the Jewish vote over extraterritorial laws against Iran and Iraq. Hence too, in large measure, Washington's lockstep support for Israel in its dealings with the Palestinians - another irritant to most of its allies.
The saddest fact, however, is that America's certainty in its own wisdom is counterproductive, its power essentially destructive. To be sure, US objections can prevent things happening: if Washington does not go along, there is no prospect of a meaningful ban on land-mines or of global curbs on pollution that will bite. But the US cannot fashion events as it wishes, in defiance of geopolitical gravity.
One day the rest of the world's patience will surely be exhausted at paying America's bills at the UN, and at a Secretary of State's mixture of pleading and bullying, that "we're sorry we can't pay - but either shut up or put up". In the case of extraterritorial sanctions against "rogue states" (as if the State Department were the only valid judge of such offenders), the position is even clearer cut. They simply don't work. And the losers are not only the American companies whose competitors snap up exports and markets that were once their own.
Washington, too, suffers from policies that merely undermine their avowed goals. In Cuba, nothing has done more to keep Fidel Castro in power than the nationalism and anti-Americanism fuelled by 35 years of sanctions designed to unseat him. In going ahead with the gas agreement, France, Russia and Iran itself all gain strength from being perceived to stand up to American bullying. Small wonder that the Clinton Administration is groping for a face-saving formula that would avoid confrontation with old allies, and keep the door ajar for better relations with what may be a less antagonistic regime in Teheran.
Ever agile, Mr Clinton will doubtless find his formula. But old glues between America and its allies are dissolving, to be replaced by new rivalries - over jobs and, probably, over the euro if the planned single currency challenges the dollar's supremacy in the world monetary arena. Today's events offer little hope of accommodation.