Paul Krugman observes that the war on Iraq is but a skirmish when compared to the Second World War.

Yet self-styled patriots are trying to impose constraints on political speech never contemplated during World War II, accusing anyone who criticizes the president of undermining the war effort.

Last week John Kerry told an audience that "what we need now is not just a regime change in Saddam Hussein and Iraq, but we need a regime change in the United States." Republicans immediately sought to portray this remark as little short of treason. "Senator Kerry crossed a grave line when he dared to suggest the replacement of America's commander in chief at a time when America is at war," declared Marc Racicot, chairman of the Republican National Committee.

Notice that Mr. Racicot wasn't criticizing Mr. Kerry's choice of words. Instead, he denounced Mr. Kerry because he "dared to suggest the replacement of America's commander in chief" — knowing full well that Mr. Kerry was simply talking about the next election. Mr. Racicot, not Mr. Kerry, is the one who crossed a grave line; never in our nation's history has it been considered unpatriotic to oppose an incumbent's re-election.

Some timid souls will suggest that critics of the Bush administration hold off until the war is over. But that's not the American tradition — and anyway, when will this war be over? Baghdad will fall, but during the occupation that follows American soldiers will still be in harm's way. Also, a strong faction within the administration wants to go on to Syria, to Iran and beyond. And Al Qaeda is still out there.

For years to come, then, this country may be, in some sense, at war. And all that time, if Mr. Racicot and his party are allowed to set the ground rules, nobody will be allowed to criticize the president or call for his electoral defeat. You know what? If that happens, we will have lost the war, whatever happens on the battlefield.