The United States of America is a nation located in North America. It is a federal-constitutional republic, and is divided into ? states. From the west to the south, the United States shares land borders with Siberia and Central America. It also shares maritime borders with the Empire of Japan by the Sea of Okhotsk and Venezuela by the Caribbean Sea. At 24,596,353 sq km, the United States is the largest country in the world, covering more than one ninth of the Earth's inhabited land area. The United States is also the third-most populated nation on the planet, the first being China; and the second being India.
As of 2012, the United States has a population underneath 315 million, ranking third in world population, behind India and China. The United States is responsible for the defense of the Panama Canal Zone, Guam, Samoa, Marianas, Wake Island, and Midway Island, as well as small non-important islands across the Pacific. The United States is a member of G-13, G-11, Pan-American Alliance, and is a permanent member in the United Nations. America possesses the second-strongest army, third largest air force, and the largest navy. It is also a nuclear weapon's state since 1947, after the detonation of Trinity on August 5, 1947 - and posses the world's largest nuclear arsenal in the world (11,921).