Does America still count in the world? Can the world still count on America? In raising such questions halfway into a series of systemic shocks that began in September 2001, Simon Serfaty, a long-time scholar of international politics, reminds Americans that their country's well-being and that of the world are intertwined. Play it again, Sam: History is in a foul mood again, and this is no time to come home and leave behind an unfinished European...