LONDON — At the Iraq inquiry in London on Jan. 29, former British Prime Minister Tony Blair found a new way to defend his decision to join George W. Bush in invading Iraq in 2003: the what-if defense. What if they hadn't invaded Iraq, and Saddam Hussein had remained in power there?

"What's important is not to ask the March 2003 Question, but to ask the 2010 Question," Blair said. "Supposing we had backed off this military action, supposing we had left Saddam and his sons, which were going to follow him, in charge of Iraq — people who used chemical weapons, caused the death of over one million people . . . If we had left Saddam in power, we would have to deal with him today, where the circumstances would be far worse."

Blair obviously thought that this was the one argument nobody could disagree with. He might have cooked the intelligence about Iraq, Saddam might not actually have had weapons of mass destruction (WMD) — Blair admits that nowadays — but if he had left this evil monster in power, we would all be sorry now.