In abandoning empire, the US could follow Britain and be a republic. Empire could turn out to be quagmire or nosedive. Narcissus fell in love with his reflection and drowned (cf. "Nemesis" by Chalmers Johnson).
to read the article by Tom Engelhardt published in: Le Monde diplomatique, June 2008, click on
http://mondediplo.com/2008/06/06ussecurity