When empires crash, everyone suffers. Usually, someone is champing at the bit to take advantage of the slightest display of imperial weakness, but one huge advantage the U.S. has today is the absence of significant enemies. Enemies it certainly has, but not one of significance, so the U.S. has what may be a unique historical opportunity for an overextended empire to downsize gently without being punished by its opponents. Of course, this will take skill, and there's the rub.
Central Asia. The increasingly obvious debacle in Central Asia is already enticing opponents to take advantage, as Russia's bribe to Kyrgyzstan to get rid of the U.S. Manas base shows. Moscow's timing was impeccable, coming on the heels of a series of highly embarrassing Taliban successes in their drive to interrupt the flow of NATO supplies through the Khyber Pass. The solution may lie in Tehran, which helped the U.S. significantly in 2001 in Afghanistan and might well do so again as part of a tension-reducing deal. In short, Washington needs a new coalition in Afghanistan but probably does not understand the local culture well enough to form one without the assistance of those living in the neighborhood.
Iran. A deal with Tehran over Central Asia leads directly to the next major step that a more modest America could take to get over its imperial hubris: recognizing that Iran has the right to pursue an independent foreign policy. Removing the burden of "regime change in Iran" from the Empire's shoulders would significantly lighten its load. Taking the pressure off Iran would also put the pressure on the Ahmadinejad administration, forcing him to pay more attention to cleaning up his domestic act, thereby further lessening the burden on the Empire.
Israel. Modifying the U.S. stance toward Israel from subservience to the ruling clique of Israeli militarists to defense of the internal security of the Israeli people would not only put U.S.-Israeli relations on a morally defensible platform but also enormously reduce the burden both in terms of finances and the harm caused to U.S. national security.
When you insist on doing everything yourself, the weight of burdens can snowball rapidly; the converse is also true.