“Since Washington’s hostile and hawkish policies have always been against the Iranian nation, this defeat is actually an obvious victory for the Iranian nation.”

—The supreme leader of Iran, Ayatollah Ali Khamenei, November 10, 2006.

Not since Dean Acheson helped provoke a North Korean invasion of the south on January 12, 1950, by stating publicly that Seoul was not part of America’s defense perimeter has a Democrat so blundered. That’s the appropriate way to describe Senator Reid’s remarks Friday at the National Press Club.

“The president does not have the authority to launch military action in Iran without first seeking congressional authorization,” the Senate majority leader said, standing next to Speaker Pelosi.

The present situation differs from the one 57 years ago in that the enemy, in this case Iran, is already in Iraq. The Iranians are manning outposts our GIs are raiding. The Iranians are infiltrating the Iraqi government and interior ministry. But the stakes for the American interest are similarly high. And there is enough ambiguity about America’s intentions in Iraq in light of the Democratic victory in November that Mr. Reid’s remarks could have the same devastating effects as Mr. Acheson’s.

Prime Minister Maliki and his government are faced with navigating a dangerous relationship with Iran. If Mr. Maliki believes America will leave the Iraqi theater too soon or that we will not be a ferocious enemy of Iran, he will be forced closer into an embrace of Iran, a country that has clearly shown its interest is not in a free and prosperous neighbor, but a chaotic one at war with itself.

The test of Mr. Maliki’s mettle, in these critical weeks, will also test the stakes of whether America can leave Iraq better than we found it, a painful proposition made so by the sabotage of Iran, Syria, Al Qaeda and other foreign powers seeking to turn this country into Lebanon of the 1980s.

President Bush has authorized a new strategy to confront head on the foreign agents seeking to destroy Iraq. Last week, for example, American soldiers raided a Sudanese mission in Baghdad. More than 400 members of Moqtada al-Sadr’s Mahdi Army have been rounded up, and reports from Baghdad and al-Anbar province suggest that Al Qaeda is on the run. It is long overdue, and every American politician is within his rights to say so.

But to criticize these necessary steps as an escalation, to rule out the prospect that our fighting men can chase these terror masters into their safe havens in Iran, is to give the Iranians a powerful talking point the next time they strong-arm Prime Minister Maliki.

Mr. Maliki, as President Bush knows, is critical to the success of our strategy to stabilize Baghdad. His advisers are writing the neighborhood by neighborhood plan. Those 21,500 troops the president is planning to send to Iraq don’t arrive until there are Iraqi battalions in place where they will embed. If Mr. Maliki believes Iran is more terrible an enemy than America is a friend, Iraq will be left to the mad mullahs in Qom. It’s natural for any congressional leader to defend the constitutional prerogatives of the legislative branch in respect of war powers. But those prerogatives will only be eroded if the legislative leaders choose to exercise them in ways that embolden America’s enemies.