Napalm is an incendiary mixture of a gelling agent and a volatile petrochemical (usually gasoline (petrol) or diesel fuel). The title is a portmanteau of the names of two of the constituents of the original thickening and gelling agents: co-precipitated aluminium salts of naphthenic acid and palmitic acid. Napalm B is the more modern version of napalm (utilizing styrene derivatives) and, although distinctly different in its chemical composition, is often referred to simply as "napalm".
A team led by chemist Louis Fieser originally developed napalm for the United States Chemical Warfare Service in 1942 in a secret laboratory at Harvard University. Of immediate first interest was its viability as an incendiary device to be used in fire bombing campaigns during World War II and its potential to be coherently projected into a solid stream that would carry for distance (instead of the bloomy fireball of pure gasoline) resulted in widespread adoption in infantry/combat engineer flamethrowers as well.
Napalm burns at the same temperature as gasoline, and for a greater duration, as well as being more easily dispersed and sticking tenaciously to its targets; these traits make it extremely effective (and controversial) in the anti-structure and antipersonnel role. It has been widely used in both the air and ground role, with the largest used to date being via air-dropped bombs in World War II (most notably in the gruesomely effective incendiary attacks on Japanese cities in 1945), and later close air support roles in Korea and Vietnam. Napalm also has fueled most of the flamethrowers (tank, ship and infantry-based) used since World War II, giving them much greater range, and was used in this role as a common (and feared) weapon of urban combat by both the Axis and the Allies in World War II. Multiple nations (including the United States, China, Russia, Iran and North Korea) maintain large stockpiles of napalm-based weapons of various types.
Napalm was used in flamethrowers, bombs and tanks in World War II. It is believed to have been formulated to burn at a specific rate and to adhere to surfaces to increase its stopping power. During combustion, napalm rapidly deoxygenates the available air and generates large amounts of carbon monoxide and carbon dioxide.
Use of fire in warfare has a long history. Greek fire, also described as "sticky fire" ( ?, pýr kolletikón), is believed to have had a petroleum base. The development of napalm was precipitated by the use of jellied gasoline mixtures by the Allied forces during World War II.Latex, used in these early forms of incendiary devices, became scarce, since natural rubber was almost impossible to obtain after the Japanese army captured the rubber plantations in Malaya, Indonesia, Vietnam, and Thailand.
This shortage of natural rubber prompted chemists at US companies such as DuPont and Standard Oil, and researchers at Harvard University, to develop factory-made alternatives--artificial rubber for all uses, including vehicle tires, tank tracks, gaskets, hoses, medical supplies and rain clothing. A team of chemists led by Louis Fieser at Harvard University was the first to develop synthetic napalm, during 1942. "The production of napalm was first entrusted to Nuodex Products, and by the middle of April 1942 they had developed a brown, dry powder that was not sticky by itself, but when mixed with gasoline turned into an extremely sticky and inflammable substance." One of Fieser's colleagues suggested adding phosphorus to the mix which increased the "ability to penetrate deeply...into the musculature, where it would continue to burn day after day."
On 4 July 1942, the first test occurred on the football field near the Harvard Business School. Tests under operational conditions were carried out at Jefferson Proving Ground on condemned farm buildings, and subsequently at Dugway Proving Ground on buildings designed and constructed to represent those to be found in German and Japanese towns. This new mixture of chemicals was widely used in the Second World War in incendiary bombs and in flamethrowers.
From 1965 to 1969, the Dow Chemical Company manufactured napalm B for the American armed forces. After news reports of napalm B's deadly and disfiguring effects were published, Dow Chemical experienced boycotts of its products, and its recruiters for new chemists, chemical engineers, etc., graduating from college were subject to campus boycotts and protests. The management of the company decided that its "first obligation was the government." Meanwhile, napalm B became a symbol for the Vietnam War.
Napalm was first employed in incendiary bombs and went on to be used as fuel for flamethrowers.
The first recorded strategic use of napalm incendiary bombs occurred in an attack by the US Army Air Force on Berlin on 6 March 1944, using American AN-M76 incendiary bombs with PT-1 (Pyrogel) filler. The first known tactical use by the USAAF was by the 368th Fighter Group, 9th Air Force Northeast of Compeigne, France 27 May 1944 (368th Fighter Group AFRHA History Documents) and the British De Havilland Mosquito FB Mk.VIs of No. 140 Wing RAF, Second Tactical Air Force on 14 July 1944, which also employed the AN-M76 incendiary in a reprisal attack on the 17th SS Panzergrenadier Division "Götz von Berlichingen" in Bonneuil-Matours. Soldiers of this Waffen SS unit had captured and then killed a British SAS prisoner-of-war, Lt. Tomos Stephens, taking part in Operation Bulbasket, and seven local Resistance fighters. Although it was not known at the time of the air strike, 31 other POWs from the same SAS unit, and an American airman who had joined up with the SAS unit, had also been executed.
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 ground troops.
Then, when the U.S. Army Air Forces on the Marianas Islands ran out of conventional thermite incendiary bombs for their B-29 Superfortresses to drop on Japanese cities, its top commanders, such as General Curtis LeMay, used napalm bombs to continue 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.
In its first known post-WWII use, U.S.-supplied napalm was used in the Greek Civil War by the Greek National Army as part of Operation Coronis against the Democratic Army of Greece (DSE) -- the military branch of the Communist Party of Greece (KKE).
Napalm was also widely used by the United States during the Korean War. These ground forces in North Korea were outnumbered at points of defense by Chinese and North Koreans, but U.S. Air Force and Navy 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 used napalm B for attacks in North Korea. Napalm was used most notably during the battle "Outpost Harry" in South Korea during the night of June 10-11, 1953. Eighth Army chemical officer Donald Bode reported that on an "average good day" UN pilots used 70,000 gallons of napalm, with approximately 60,000 gallons of this thrown by US forces. In John Ford's 1951 documentary, This is Korea, footage of napalm deployment is accompanied by a voice-over by John Wayne saying, "Burn 'em out, cook 'em, fry 'em"; the New York Herald Tribune hailed "Napalm, the No. 1 Weapon in Korea".Winston Churchill, among others, criticized American use of napalm in Korea, calling it "very cruel", as the US/UN forces, he said, were "splashing it all over the civilian population", "tortur[ing] great masses of people". The American official who took this statement declined to publicize it.
Napalm became an intrinsic element of U.S. military action during the Vietnam War as forces made increasing use of it for its tactical and psychological effects. Reportedly about 388,000 tons of U.S. napalm bombs were dropped in the region between 1963 and 1973, compared to 32,357 tons used over three years in the Korean War, and 16,500 tons dropped on Japan in 1945. The U.S. Air Force and U.S. Navy used napalm with great effect against all kinds of targets, such as troops, tanks, buildings, jungles, and even railroad tunnels. The effect was not always purely physical as napalm had psychological effects on the enemy as well.
A variant of napalm was produced in Rhodesia for a type of ordnance known as Frantan between 1968 and 1978 and was deployed extensively by the Rhodesian Air Force during that country's bush war. In May 1978, Herbert Ushewokunze, minister of health for the Zimbabwe African National Union (ZANU) produced photographic evidence of purported civilian victims of Rhodesian napalm strikes, which he circulated during a tour of the US. The government of Mozambique and the Zimbabwe African People's Union (ZAPU) also issued claims at around the same time that napalm strikes against guerrilla targets had become a common feature in Rhodesian military operations both at home and abroad.
Other instances of napalm's use include by France during the First Indochina War (1946-1954), the Algerian War (1954-1962), the Portuguese Colonial War (1961-1974), the Six-Day War by Israel (1967), in Nigeria (1969), India and Pakistan (1965 and 1971), Egypt (1973), by Morocco during the Western Sahara War (1975-1991), by Argentina (1982), by Iran (1980-88), by Iraq (1980-88, 1991), By IPKF (Indian Peace keeping force) in 1987 against Tamils (LTTE)in Sri Lanka, by Angola during the Angolan Civil War, and Yugoslavia (1991-1996). Recently, Turkey has been accused of using Napalm in its war against Kurdish militias over Afrin. Turkey's General Staff, however, denies this.
When used as a part of an incendiary weapon, napalm can cause severe burns (ranging from superficial to subdermal), asphyxiation, unconsciousness, and death. In this implementation, napalm fires can create an atmosphere of greater than 20% carbon monoxide and firestorms with self-perpetuating winds of up to 70 miles per hour (110 km/h).
Napalm is effective against dug-in enemy personnel. The burning incendiary composition flows into foxholes, trenches and bunkers, and drainage and irrigation ditches and other improvised troop shelters. Even people in undamaged shelters can be killed by hyperthermia, radiant heat, dehydration, asphyxiation, smoke exposure, or carbon monoxide poisoning.
One firebomb released from a low-flying plane can damage an area of 2,500 square yards (2,100 m2).
International law does not specifically prohibit the use of napalm or other incendiaries against military targets, but use against civilian populations was banned by the United Nations Convention on Certain Conventional Weapons (CCW) in 1980.Protocol III of the CCW restricts the use of all incendiary weapons, but a number of countries have not acceded to all of the protocols of the CCW. According to the Stockholm International Peace Research Institute (SIPRI), countries are considered a party to the convention, which entered into force as international law in December 1983, as long as they ratify at least two of the five protocols. Approximately 25 years after the General Assembly adopted it, the United States signed it on January 21, 2009, President Barack Obama's first full day in office. Its ratification, however, is subject to a reservation that says that the treaty can be ignored if it would save civilian lives.