The 2009 Nobel Peace Prize honored Obama for furthering a 'vision of a world free from nuclear arms'. Just five years after Obama's Nobel Peace Prize, the projected US nuclear weapons spending over the next 30 years hit $1 Trillion. The US spent more in 2014 on nuclear weapons research, development, testing and production than ever ($11 billion), including during World War II. Obama campaigned on shrinking America's nuclear arsenal. Plans call for modernizing US nuclear weapons to make it better leverage and force the world to shrink arsenals everywhere.
On top of that, Obama is waging various different military operations against multiple nations. Because Obama is waging various wars, and has increased America's Nuclear budget to unprecedented levels, he should return the Nobel Prize.