7. Turkey, 664,060The Turkish army traces its roots to the Ottoman Empire, though it disintegrated in the aftermath of its defeat in World War I.
The country remained neutral until the closing months of World War II, when it finally joined the Allies that were on the cusp of victory.
The country then initiated a massive modernization program of its military after joining the North Atlantic Treaty Organization, or NATO, in 1952. It sent troops to the Korean War.
The Turkish army has also sent operational staff to the multinational army corps initiative of the European Union and NATO.