What it is

"Napalm" means any petrochemical — for example, gasoline, kerosene, or benzene — that has had chemicals added to it to thicken, or gel, it and make it function more effectively as an incendiary. Napalms are stickier, and burn hotter, than unadulterated hydrocarbons. As the Oxford English Dictionary writes, it is "A thixotropic gel consisting of petrol and this thickening agent (or some similar agent), used in flame-throwers and incendiary bombs; jellied petrol."

Who invented it

Harvard Chemistry Professor Louis Fieser and his associate E. B. Hershberg on Valentine's Day 1942 in a top secret university war research laboratory in the basement of the Converse Chemistry Laboratory on Oxford Street in Cambridge, Massachusetts. Fieser and Hershberg and their colleagues tested the first napalm bomb on the Harvard College soccer field, between the Business School and the football stadium, on July 4. 

Why it was invented

For use as an incendiary weapon. Its creators said they expected it would be used against structures. "I couldn’t foresee that this stuff was going to be used against babies and Buddhists. The person who makes a rifle … he isn’t responsible if it is used to shoot the President," Fieser told journalist John Lannan in November, 1967. 

Where has it been used

In most of the world's major military conflicts since its creation: most frequently, widely, in the greatest quantities and over the longest period of time by the United States, but also by Cuba, Peru, Bolivia, Brazil, Britain, France, the Soviet Union, Portugal, Israel, Egypt, Turkey, Iraq, India, Ethiopia, Thailand, El Salvador, and Argentina, among others. Its first use in combat was on 15 December 1943 in Sicily when U.S. troops incinerated a wheat field believed to shelter Germans. Napalm bombs first saw combat on 15 February 1944 when the U.S. attacked Japanese forces in the town of Pohnpei, capital of the eponymous Micronesian island 2,500 miles southwest of Hawaii and 1,800 miles northeast of Australia. Its most recent use was by U.S. forces during the 2003 invasion of Iraq.

Legal status

Napalm is legal to use on the battlefield under international law. Its use against "concentrations of civilians" is a war crime.

Agent Orange

Is an herbicide. It not napalm.

Complete source documentation is included in Napalm, An American Biography.

Napalm was invented on Valentine's Day 1942 in a top-secret Harvard University weapons research laboratory in Cambridge, Massachusetts. Professor Louis Fieser tested the first napalm bomb on the Harvard College soccer field that Independence Day. It went on to support the Allies in Europe, incinerate 64 of Japan's 67 largest cities, and help America win World War II: the Bomb got the press, but napalm did the work.

1942: Harvard University test of white phosphorus igniter in napalm bomb. Louis Fieser, The Scientific Method.

Napalm describes any form of thickened hydrocarbon: torturously hot and sticky when ignited, stable at high and low temperatures, cheap, easy to transport, and simple to prepare. It is one of the most devastating weapons ever invented. 

Air force commanders around the world embraced incendiary gel after they observed its effectiveness. Greek bombers used U.S. napalm to annihilate civil war enemies in 1948. Napalm held the line against communism in Korea in 1950. United Nations forces eventually dropped about twice as much on the peninsula as fell on Japan during WWII. In 1952, an American patent made Fieser's formula public.

1945: Osaka incinerated by napalm. U.S.Army

Napalm has subsequently been used in most of the world's major military conflicts. Cuba, Peru, Bolivia, Brazil, Britain, France, the Soviet Union, Portugal, Israel, Egypt, Turkey, Iraq, India, Ethiopia, Thailand, El Salvador, and Argentina are among the states that have attacked enemies with the gel. It was most recently used by the United States during the 2003 invasion of Iraq.

From the book:

Americans applauded front page stories on the incineration of Tokyo and the firebombing of other Japanese cities. During the Korean war, The New York Times and other newspapers printed hundreds of articles that mentioned napalm. Criticism, if it occurred at all, was fleeting.

1967: University of Wisconsin-Madison protest against napalm and the Vietnam War. UW-Madison Archives 

Vietnam changed this paradigm. For the first time, napalm’s horrific effects on civilians, especially children, received sustained attention in the United States. A grass-roots protest movement against the incendiary and its manufacturer Dow Chemical Corporation began in northern California in 1965. It spread across the country in the late 1960s, and linked business, weapon, war and country so effectively, and received such wide publicity, that napalm came to symbolize for many all that was objectionable about American involvement in Vietnam.

In 1972, as debacle loomed for U.S. forces, “The Terror of War” photograph of nine-year-old Kim Phúc, burned naked as she ran to escape fighting, became an icon. Defeat in 1975 took napalm’s reputation, and much of America’s, with it. Movies, songs, artworks, poems, books and articles produced during and especially after the Vietnam War popularized the anti-war movement’s argument, and made napalm a worldwide synonym for American brutality.

International law globalized and codified this new antipathy. Diplomats and attorneys, who showed little interest in napalm for the first decades of its existence, convened conferences and drafted rules to limit its deployment starting in the late 1960s. In 1980, United Nations delegates adopted many of their proposals when they approved Protocol III of the Convention on Certain Conventional Weapons. Incendiary attacks against “concentrations of civilians” became war crimes. Most of America’s allies and greatest adversaries, their way smoothed by development of alternate military technologies, endorsed the compact in relatively short order.

1980: United Nations Convention on Certain Conventional Weapons Protocol III regulates napalm. United Nations Office at Geneva.

America refused to accept the world’s judgment. Presidents Ronald Reagan and George H. W. Bush did not even submit Protocol III to the Senate for discussion. Over time, however, events changed the calculus of national advantage. Commanders in Chief came to appreciate the benefits of working within global consensus. President Bill Clinton and his successor George W. Bush changed course, and urged ratification. In 2008, in the face of multilateral alliances assembled to regulate landmines and cluster munitions, and concern that international law to manage conventional weapons was slipping out of U.N. control, senators ratified the protocol. President Barack Obama signed it in 2009. A diplomatic reservation attached by the president, however, asserted that the United States could disregard the treaty at its discretion if doing so would save civilian lives. This provision, of questionable legal validity (although no doubt valid enough in practice), suggests nostalgia for unilateralism.

In 1945 we “scorched and boiled and baked to death more people in Tokyo on that night of March 9-10 than went up in vapor at Hiroshima and Nagasaki combined,” U.S. General Curtis LeMay, who directed all three attacks, wrote after the war. In 2012, however, as Bell Helicopter observed in promotional literature for its napalm-capable Cobra gunship, “the number one challenge facing armed forces on today’s battlefields is the requirement to positively identify friend from foe and then be able to attack hostile targets with precision munitions so as to reduce or eliminate collateral damage to civilian personnel and property.”

1993: U.S. F/A 18 Hornet aircraft loaded with MK-17 napalm bomb. U.S. Naval Air Station, Fallon, Nevada

Napalm’s flames limn this arc. In 1945, it was an American hero that helped win the fight against fascism. In 1950, it held the line against communism in Korea. It served with distinction for most, or all, of the Vietnam war. Today it is a war criminal on probation, its use against concentrations of civilians banned by international covenant and its deployment against anyone else tightly restricted by the law of public opinion.

Fire’s savagery as a weapon has not changed since World War II, or even since the time of Hercules. Hydrocarbon-based incendiaries, although there are alternatives, offer proven, cost-effective military solutions. What has changed in napalm’s lifetime is America’s defeat in Vietnam, and the rise of a global society. Incendiary gel is a symbol of the former: stigmatized to the point of monstrosity, and unmentionable for leaders. Its fate is a searing example of the authority of the latter.

Click here to see more images from the book.