After 1945
The Korean War was the first major conflict following World War II. New devices, including smaller radios and the helicopter were also introduced. Parachute drops, which tended to scatter a large number of men over the battlefield, were replaced by airmobile operations using helicopters to deliver men in a precise manner. Helicopters also provided fire support in many cases, and could be rushed to deliver precision strikes on the enemy. Thus, infantry were free to range far beyond the conventional fixed artillery positions. They could even operate behind enemy lines, and later be extracted by air. This led to the concept of vertical envelopment (originally conceived for airborne), in which the enemy is not flanked to the left or right, but rather from above.
Read more about this topic: Infantry Tactics