T-72 Tank first entered service with the Soviet Union in 1971 during the Cold War. It was a very successful series of tanks and over 20,000 have been produced. T-72 was widely exported and is a veteran of many years of hard combat in the Iran-Iraq War, the Georgian Civil War, the Gulf War, the Wars in Chechnya, the war in Ukraine and many others. The T-72 has a smoothbore 125mm gun and heavy armor and later versions had resin spaced armor. They have been built in Poland, Czechoslovakia, and even Iran.