You would think that Senators Carl Levin and John McCain would have learned by now that you cannot deal in good faith with a White House that does not act in good faith. Yet both men struck bargains intended to restore the rule of law to American prison camps. And President Bush tossed them aside at the first opportunity. Mr. Bush made a grand show of inviting Mr. McCain into the Oval Office last month to announce his support for a bill to require humane treatment of detainees at Guantánamo Bay and other prisons run by the American military and...