The Soviet T 55 medium tank, along with its T 59 Chinese replica is the most widespread tank in the world. Fifty years after its initial design planning and subsequent up-dates, it is still utilised by the armed forces of many countries. The T 55 has been the protagonist of the main conflicts over the last fifty years, from the invasion of Czechoslovakia to the conflict in Vietnam, from the Arab-Israeli war to Operation Desert Storm and even Operation Enduring Freedom, the most recent major conflict in Iraq. In all these wartime events, the T 55 tank has always distinguished itself (if handled by well-trained personnel) when compared with combat vehicles of equal technology, thereby demonstrating the validity of its formula.