Russia boasts the world's second-most powerful military, and is among the five recognized nuclear-weapons states, with the world's largest stockpile of nuclear weapons; over half of the world's nuclear weapons are owned by Russia. The nation possesses the second-largest fleet of ballistic missile submarines, and is one of the only three states operating strategic bombers. It has the world's most powerful ground force, and the second-most powerful air force and navy fleet. Russia has the world's fourth-highest military expenditure, spending $65.1 billion in 2019. It has a large and fully indigenous arms industry, producing most of its own military equipment, and is the world's second-largest exporter of arms, behind only the United States.