Conveniently nestled between silicon and sulfur on the periodic table, phosphorus is one of nature's trendiest and most useful chemical elements. It was discovered in 1669 by a German alchemist named Hennig Brand, the unintended result of Brand's attempt to make gold by boiling concentrated urine. Bizarre, but true.
White phosphorus is a man-made variation of the phosphorus that's mainly used to manufacture phosphoric acid. Phosphoric acid is used to make fertilizers and cleansers. Phosphoric acid also is used as a food additive. It helps give Coke and Diet Coke some of its tanginess. In addition, phosphoric acid once was an ingredient in rat poison.
The U.S. military has a whole other set of uses for white phosphorus (or WP, as it's usually abbreviated). They burn it to produce a smoke so dense that it conceals troop movements and positions. And they burn it to produce the opposite effect: WP burns so brightly that it can used like a flying flare to illuminate battlefields.
They also burn it to kill people. WP is a very effective incendiary weapon (an incendiary is a weapon that sets something on fire, as opposed to just blowing it up). Throughout the 20th century, WP was used in grenades and artillery. If someone is, say, hiding in a bunker that's proving somewhat impervious to shooting or bombing, then a WP weapon can be used to attack the people in the bunker without hitting them directly.
Here's how: When a WP munition goes off, it disperses a cloud of WP dust. Unlike your run-of-the-mill dust, WP dust spontaneously ignites when it reaches just 86 degrees. Therefore, when the dust comes into contact with skin (98.6 degrees or so), it will burn. The burning will not stop until all the WP is used up or until its oxygen supply is cut off. Basically, WP burns people alive. People killed with WP sometimes look like they've been dipped in acid.
WP is in the news again because it turns out the U.S. Marines used it as an incendiary weapon during Operation Phantom Fury, the November 2004 assault on the Iraqi city of Fallujah. At first, the United States denied using incendiary WP weapons. In a statement circulated by the State Department to counter what it called "myths" about the Fallujah battle, it asserted that WP was used "sparingly" and only "for illumination." "They were fired into the air to illuminate enemy positions at night, not at enemy fighters," the statement said.
Eventually, though, the truth got out. Writing in the March-April 2005 issue of Field Artillery magazine (subscribe now and receive a grenade-phone and stylish tote bag!), three Marines who fought in Fallujah mention how WP shells were used to force people out of hiding places. After bloggers and the regular media discovered the article, the Pentagon was forced to 'fess up.
Why deny using WP as an incendiary? Because using incendiaries on or near civilians generally is regarded as illegal, and the Pentagon knows it. News images from Vietnam (most famously the footage of the naked, burned Vietnamese child running from a U.S. napalm attack on her home) soured world opinion on the use of incendiary weapons. In 1980, an international treaty was enacted, forbidding the use of incendiaries on civilians.
Additionally, some argue that WP is a chemical weapon. Like mustard gas or VX nerve agent, WP kills because of the chemical reactions it initiates when it contacts humans (i.e., burning). When you consider that every argument for invading Iraq included a reminder that Saddam Hussein was evil for using chemical weapons on fellow Iraqis, it seems not only hypocritical for us to turn around and use WP but inconceivably stupid.
But was using WP in Fallujah illegal? No, because the United States did not sign the 1980 treaty banning incendiaries against humans. And because WP's chemical reaction kills with heat (i.e., burning flesh) instead of poisoning, WP is not prohibited by the 1993 Chemical Weapons Convention ban, either.
But in a war that's supposed to win the "hearts and minds" not only of Iraqis, but of the Arab world, who cares? Hair-splitting isn't going to convince anyone that using WP in an urban area filled with civilians is a good idea. WP is effective as a tactical weapon, but what's the point of tactical effectiveness when a weapon's use undermines the war's strategic goals, not to mention what's left of the United States' reputation?