Somewhat overstated. The US remains the largest economy in the World, the most significant military power, and, as they never stop telling us, the paymaster of the significant international institutions.
I think that it is right to say that in the nineteen-seventies, Europe (principally Germany) and Japan emerged as significant challenges to US hegemony, disrupting the post-war settlement with such force that it fragmented the detente between the US and the Stalinist bloc.
(It was America's attempt to impose its will on its allies by re- politicising international relations, the 'Second Cold War' that triggered the collapse of the USSR.)
The conditions of the defeat of the West's opponents in the East have tended to re-establish America's pre-eminence, not dislodge it, as in Iraq, Somalia, Bosnia, Kosovo etc. It is noticeable that the last significant European conflict was fought by Nato, not a UN force, under US military command.
And while Japan by no means fell as far as was predicted in the East Asian crisis, the striking condition of the Eighties, in which Japan became creditor to the US has been overcome. The Euro, too, is not looking that healthy.
Evil empire? Empire certainly, and one that pursues its own interests at the expense of the peoples of the less developed world as it ignores those of its own citizens. And, yes, I would say that the balance sheet puts Western military intervention in the third world as a barrier to human development, not a boon. -- James Heartfield