Tanks in the Cold War Korean War M24 Chaffee's were the first U.S. tanks to fight the North Korean T-34-85s. The Chaffee fared poorly against these much better-armed and armored medium tanks. Chaffees were more successful later in the war in their reconnaissance role, supported by heavier tanks such as the M4 Sherman, M26 Pershing, and M46 Patton. The heavier but older Pershing was deemed unsatisfactory due to its inferior mobility, which was unsuitable for a medium tank role as it used the same engine that powered the much lighter M4 Sherman, and 1949, the upgraded M26 received a new power plant and a main
Tanks in the Cold War at long range. The World War II concept of heavy tanks, armed with the most powerful guns and heaviest armour, became obsolete since they were just as vulnerable as other vehicles to the new medium tanks. Likewise, World War II had shown that lightly armed, lightly armoured tanks were of little value in most roles. Even reconnaissance vehicles shown a trend towards heavier weight and greater firepower during World War II; speed was not a substitute for armor and firepower. An increasing variety of anti-tank weapons and the perceived threat of a nuclear war prioritized the need for additional armor.