Tanks in World War II the North African campaign. It continued to serve in the Red Army for some time, and in a single campaign in the Pacific. Red Army crews nicknamed it "grave for seven brothers" referring to the seven-man crew. The most important American design of the war was the M4 Medium Tank, or "Sherman" in British service. The M4 Medium became the second-most-produced tank of World War II, and was the only tank to be used by virtually all Allied forces (thanks to the American lend-lease program); approximately 40,000 M4 Mediums were produced during the war. M4s formed the main tank of
Opposition to the war in Afghanistan (2001–2014) entering an eleventh year on October 7, 2011 and marking for the U.S. the longest period of sustained warfare in its history – greater than the time the United States was involved in World War I, World War II and the Korean War combined.<ref name="War and Sacrifice in the Post-9/11 Era"></ref> The war in Afghanistan surpassed the length of official U.S. participation in the Vietnam War, 8 years and 5 months, in the spring of 2010 to become the longest-running U.S. war ever. According to a study by the RAND Corporation, an American think tank working for the U.S. military,