The M270 Multiple Launch Rocket System (M270 MLRS) is an armored, self-propelled, multiple rocket launcher; a type of rocket artillery.
Since the first M270s were delivered to the U.S. Army in 1983, the MLRS has been adopted by several NATO countries. Some 1,300 M270 systems have been manufactured in the United States and in Europe, along with more than 700,000 rockets. The production of the M270 ended in 2003 when the last batch was delivered to the Egyptian Army.
In the early 1970s, the Soviet Union had a clear advantage over U.S. and NATO forces in terms of rocket artillery. Soviet tactics of bombardment by large numbers of truck-mounted MRLs, such as the BM-21, would saturate a target area with thousands of rockets, ensuring some would hit specific targets while delivering a psychological impact. By contrast, U.S. artillerists favored cannon artillery for its relative accuracy and ammunition conservation over "area fire" rockets, and as a result, we're left with a small amount of World War 2 vintage rocket artillery.