For the longest time, a certain admirable, independent senator from Arizona disappeared from public life, replaced by an irresponsible, opportunistic and occasionally demagogic figure, who seemed to have been warped by his presidential ambitions and his disappointment in losing. But John McCain has now returned, just in time to refute the sinister attempt by his fellow Republicans to justify torture as the instrument of Osama bin Laden's demise.

During the last administration, even as a supporter of the Iraq invasion and the "war on terror," McCain broke ranks with his party to protest the worst excesses of the George W. Bush presidency. In one of the most memorable moments of the otherwise desultory Republican primary debates in 2008, he cited the Constitution, the Geneva Conventions and American military tradition to upbraid Mitt Romney for waffling on the issue of waterboarding. "This is what America is all about," he said indignantly. "This is a defining issue."

With every right-wing enabler from John Yoo to Marc Thiessen to Liz Cheney suddenly stepping forward to suggest that that the death of bin Laden absolves Bush-era criminality, it is refreshing to hear McCain's clear, strong voice of opposition. The torture advocates have claimed that the waterboarding of Khalid Sheikh Mohammed, a high-ranking leader in al-Qaida and an alleged mastermind of the 9/11 attack, caused him to reveal the identity of a courier whose trail led, almost seven years later, to the hideout in Abbotabad, Pakistan.

McCain is having none of this nonsense, as he explains in a blistering essay published in The Washington Post:

"The trail to bin Laden did not begin with a disclosure from Khalid Sheikh Mohammed, who was waterboarded 183 times. The first mention of Abu Ahmed al-Kuwaiti -- the nickname of the al-Qaida courier who ultimately led us to bin Laden -- as well as a description of him as an important member of al-Qaida, came from a detainee held in another country, who we believe was not tortured. None of the three detainees who were waterboarded provided Abu Ahmed's real name, his whereabouts or an accurate description of his role in al-Qaida. In fact, the use of 'enhanced interrogation techniques' on Khalid Sheikh Mohammed produced false and misleading information."