The United States remained by far the world’s biggest spender in 2015

"The United States remained by far the world’s biggest spender in 2015, despite its expenditure falling by 2.4 per cent to $596 billion. Among the other top spenders, China’s expenditure rose by 7.4 per cent to $215 billion, Saudi Arabia’s grew by 5.7 per cent to $87.2 billion—making it the world’s third-largest spender—and Russia’s increased by 7.5 per cent to $66.4 billion."