Age: 63
Occupation: Secretary of State
Previous TIME 100 appearances: 4
Crisis management has become something of a routine for Hillary Clinton. By definition, U.S. Secretaries of State confront international dustups of every variety. But an avalanche of change throughout the Arab world has put Obama's chief diplomat in the uncomfortable position of trying to formulate a coherent policy across a single region made up of multiple nations that affect U.S. interests in very different ways. Yet if reports are to be believed, Clinton has insisted on at least one rule that applies to them all: the U.S. must take unequivocal stands against oppressive dictators. A veteran of the international scene, she had the foresight to warn Arab leaders in January that they risked "sinking into the sand" if they didn't move on democratic reforms. But she's also managed the unprecedented challenge of the WikiLeaks cables. In the tranche of documents released online, she was quoted as saying certain heads of state need psychiatric help, among other embarrassing nuggets. But Clinton has defied skeptics who said she could no longer lead American foreign policy after the leaks.