Napalm was first employed in incendiary bombs and went on to be used as fuel for flamethrowers.
Napalm bombs burned out 40% of the area of Japanese target cities in the World War..
The first recorded use of napalm incendiary bombs was on July 17, 1944, when 14 American P-38 Lightning aircraft of the 402d Fighter Squadron / 370th Fighter Group dropped them on a fuel depot at Coutances, near St. Lô, France. Further use of napalm by American forces occurred in the Pacific Theater of Operations, where in 1944 and 1945, napalm was used as a tactical weapon against Japanese bunkers, pillboxes, tunnels, and other fortifications, especially on Saipan, Iwo Jima, the Philippines, and Okinawa, where deeply dug-in Japanese troops refused to surrender. Napalm bombs were dropped by aviators of the U.S. Navy, the United States Army Air Forces, and the U.S. Marine Corps in support of their ground troops.
Then, when the U.S. Army Air Forces on the Marianas Islands ran out of conventional thermite incendiary bombs for its B-29 Superfortresses to drop on Japanese cities, its top commanders, such as General Curtis E. LeMay turned to napalm bombs to continue its fire raids on the large Japanese cities.
In the European Theater of Operations napalm was used by American forces in the siege of La Rochelle in April 1945 against German soldiers (and inadvertently French civilians in Royan) - about two weeks before the end of the war.
Napalm B was also used during the Greek Civil War between the Greek Army and Communist rebels. During the last year of this Civil War, 1949, the United States increased its military aid to the Greek Government by introducing a new weapon to finish off the war: napalm B. The first napalm attack in Greece took place on the mountain of Grammos, which was the stronghold of the Communist rebels.
Napalm B was also widely used by the United Nations military forces during the Korean War. These Allied ground forces in Korea were frequently outnumbered, and greatly, by their Chinese and North Korean attackers, but the U.S. Air Force and the U.S. Navy naval aviators had control of the air over nearly all of the Korean Peninsula. Hence, close air support of the ground troops along the border between North Korea and South Korea was vital, and the American and other U.N. aviators turned to napalm B as an important weapon for defending against communist ground attacks.