In a little-noticed but highly significant interview aired Thursday evening by Fox News Channel, the chief American weapons inspector in Iraq, Charles Duelfer, said, “We found, you know, 10 or 12 sarin and mustard rounds.”

Mr. Duelfer is the successor to David Kay as the top American in Iraq searching for Saddam Hussein’s weapons of mass destruction. Mr. Kay, you may recall, is the man who became famous when, after months of searching, he returned to Washington and pronounced to the Senate Armed Services Committee in January, 2004, “We were all wrong” about the presence of weapons of mass destruction in Iraq.

That claim was bannered on headlines of newspapers around the world and has become ingrained in American political discourse. “There were no weapons of mass destruction in Iraq,”Al Gore said on June 24, 2004. New York Times columnist Paul Krugman wrote it May 11: “We found no weapons of mass destruction.” New York Times columnist Thomas Friedman wrote it April 8, 2004: “There are no weapons of mass destruction in Iraq.” New York Times columnist Bob Herbert wrote it February 6, 2004: “There were no weapons of mass destruction.” Howard Dean said on CNN April 4, 2004, “There were no weapons of mass destruction.

Now we learn from Mr. Duelfer that he has discovered not one, not two, but “10 or 12 sarin and mustard rounds.”

That may not sound like much. But it’s serious. The Web site of the Council on Foreign Relations, hardly a front for Iraq war hawks, says, “One hundred milligrams of sarin — about one drop — can kill the average person in a few minutes if he or she’s not given an antidote. Experts say sarin is more than 500 times as toxic as cyanide.” If Mr. Duelfer was able to find these shells in a vast country amid a population still intimidated by anti-American violence, there are more to be found. Even Mr. Kay, testifying to Congress on October 2, 2003, reported that Americans had found “a vial of live C. botulinum Okra B. from which a biological agent can be produced.…hidden in the home” of an Iraqi biological weapons scientist. The New York Sun has reported on the 7-pound block of cyanide salt found in the Baghdad safehouse of Abu Musab al-Zarqawi in January 2004.

Sarin. Mustard gas. Botulinum. Cyanide salt. It’s getting harder to claim that there were no weapons of mass destruction in Iraq. These columns argued against making disarmament the main reason for war, preferring an emphasis on freedom and democratization as outlined in the Iraq Liberation Act. Still, the disclosures remind us that we’d much rather have American soldiers and intelligence officers hunting for these weapons on foreign soil. The alternative would be to have American police and firemen and FBI agents swarming over the scene of a terrorist attack here in New York, trying to figure out after the fact what deadly substance had been used against us and where it came from.