A controversial microwave weapon called the Active Denial System has been recalled from Afghanistan, according to an Air Force spokesperson. The pain gun generates a targeted burning sensation in humans using millimeter waves. The device was plagued by a series of technical and safety issues. On top of that, a number of public commentators opposed it on humanitarian grounds. There's no official explanation for the recall, but here's what critics have said about it in recent weeks:

  • What Is the Active Denial System?  Sharon Weinberger at AOL News describes it as a "controversial nonlethal weapon that uses microwave energy to create intense pain...The weapon is designed to shoot an invisible beam of energy at people, creating an intense burning sensation that forces them to flee. The Air Force has called it the 'goodbye effect.'"

  • It's Very Effective, writes the Wall Street Journal's Nathan Hodge, who felt the effects of it firsthand: "I dutifully took my turn. Even though I was standing several hundred meters downrange, I could immediately feel the heat when the operator fired. It wasn’t that bad, at first: It was a miserably cold morning, and pain ray gave a nice blast of heat, like someone had opened an oven door right in front of me. But it quickly became unbearable. Instinctively, I stepped away."

  • Will This Really Help the War Effort? wonders Noah Shachtman at Wired: "I’m sure they’re telling themselves that the generally non-lethal microwave weapon is a better, safer crowd control alternative than an M-16. But those ray-gun advocates better think long and hard about the Taliban’s propaganda bonanza when news leaks of the Americans zapping Afghans until they feel roasted alive."

  • This Tactic Is Unconscionable, writes Digby at Hullabaloo: "Setting aside the fact that using a 'pain ray' in general is a horrible idea, how much more horrible is it to use in a country that already sees itself invaded by men who look like robot insects and where unmanned planes kill targets from a distance? It's hard not to see that as a weapons laboratory on a people who have no means to protest."

  • A Disturbing Trend, writes Ando Arike at Harper's: "Although 'first-generation' weapons like rubber bullets and pepper spray have gained a certain acceptance, despite their many drawbacks, exotic technologies like the Active Denial System invariably cause public alarm. Nevertheless,The trend is now away from chemical and 'kinetic' weapons that rely on physical trauma and toward post-kinetic weapons that, as researchers put it, 'induce behavioral modification' more discreetly. One indication that the public may come to accept these new weapons has been the successful introduction of the Taser—apparently, even the taboo on electroshock can be overcome given the proper political climate."