Brazil is hungry to lead. It’s orchestrating this summer’s World Cup, leading 32 nations as they battle for fútbol victory. It will host the 2016 Summer Olympics. And late last year, it helped spark the global movement to Balkanize Internet governance. But is Brazil also ready to lead on climate change? What about nuclear non-proliferation? Human rights? In other words, is Brazil prepared to be a constructive actor on the international stage, or has it become a gadfly?