Age: 44
Occupation: U.K. Prime Minister
Previous TIME 100 appearances: 0
"I think you just get on with it. It's the best thing to do in politics rather than trying to endlessly work out the definition of who you are or what you're about." That was Cameron to TIME in 2008, two years before he became Britain's Prime Minister, describing a pragmatic approach that has seen the once staunch Conservatives cohabit happily in coalition with Liberal Democrats and allowed him to pivot from his criticisms of his Downing Street predecessor Tony Blair's "liberal interventionism without a handbrake" to argue forcefully for international action to protect Libyan citizens. His efforts proved decisive in securing the U.N. resolution, but that's not the only reason the world is watching this first-time leader with interest. His government is presiding over eye-watering austerity measures that he vows will strengthen the economy but sent angry Britons onto the streets amid warnings the cuts may tip the U.K. back into recession; if he's right, expect Cameron — and Cameronism — to be widely imitated.