From time to time, South Korea has sent its troops overseas to assist American forces. It has participated in most major conflicts that the United States has been involved in the past 50 years. South Korea dispatched 325,517 troops to fight alongside American, Australian, Filipino, New Zealand and South Vietnamese soldiers in the Vietnam War, with a peak strength of 50,000. In 2004, South Korea sent 3,300 troops of the Zaytun Division to help re-building in northern Iraq, and was the third largest contributor in the coalition forces after only the US and Britain. Beginning in 2001, South Korea had so far deployed 24,000 troops in the Middle East region to support the War on Terrorism. A further 1,800 were deployed since 2007 to reinforce UN peacekeeping forces in Lebanon.