World military spending grows to $1.7tn in 2015. The US defense budget at $596 billion still makes it the world’s largest military spender, nearly three times second place China with $215 billion, according to a report from the Stockholm International Peace Research Institute (SIPRI). Washington still spends 36 percent of the world’s total arms budget. Ruble depreciation has pushed Russia from the top three. Saudi Arabia overtook Russia’s position, spending $87.2 billion on its military program last year, compared to Moscow’s $66.4 billion.