Q. Where is the line between torture and non-torture?
A. There is no line. Thank you for playing:

For reporting illegal arms sales, Navy veteran Donald Vance says he was imprisoned by the U.S. military and subjected to harsh interrogation methods.

Also held was colleague Nathan Ertel, who helped Mr. Vance gather evidence documenting the sales, according to a federal lawsuit both have filed in Chicago, alleging they were illegally imprisoned and subjected to physical and mental interrogation tactics “reserved for terrorists and so-called enemy combatants.”

Navy Capt. John Fleming, a spokesman for U.S. detention operations in Iraq, confirmed the detentions but said he could provide no details because of the lawsuit.

There were times Mr. Vance began to wish he had just kept his mouth shut, as he huddled on the floor in solitary confinement with that head-banging music blaring dawn to dusk and interrogators yelling the same questions over and over.

He had thought he was doing a noble thing when he started telling the FBI about the guns and the land mines and the rocket-launchers — all of them being sold for cash, no receipts necessary, he said.

He told a federal agent the buyers were Iraqi insurgents, American soldiers, State Department workers, and Iraqi Embassy and ministry employees.

The seller, he said, was the Iraqi-owned company he worked for, Shield Group Security.

“It was a Wal-Mart for guns,” he says. “It was all illegal, and everyone knew it.”

So Mr. Vance says he blew the whistle, supplying photos and documents and other intelligence to an FBI agent in his hometown of Chicago because he didn’t know whom to trust in Iraq.

For his trouble, he says, he got 97 days in Camp Cropper, a U.S. military prison that once held Saddam Hussein, and he was classified a security detainee.