IEDs are generally seen in terrorist actions or in asymmetric unconventional warfare by insurgent guerrillas or commando forces in a theatre of operations. In the Iraq War (2003–2011) insurgents used IEDs extensively against U.S.-led forces and, by the end of 2007, IEDs were responsible for approximately 63% of coalition deaths in Iraq. They were also used in Afghanistan by insurgent groups, and have caused over 66% of coalition casualties in the 2001–2021 Afghanistan War.