As the missiles fly and the tanks roll forward in Iraq, Congress has mostly closed ranks to support the troops. The hope is for an early victory with relatively few casualties, although the last three days show the possibility remains for a longer, tougher combat.

The Senate voted unanimously to support the troops, support President Bush and thank British Prime Minister Tony Blair for being a staunch ally. Sen. Edward Kennedy, D-Mass., a leading opponent of the war plan, pledged united support of “the men and women of our armed forces.” The House of Representatives passed its version, focused heavily on commending the Republican president, in an overwhelming 392-11 vote. A few disagreed. Rep. Jim McDermott, D-Wash., said, “I for one will not be forced to praise the president’s reckless decisions when what I want to do is praise the troops.”

Without questioning the motives of the members of Congress, it can be added that any who might be viewed as failing to support the troops would face substantial political risk.

Closing ranks is as it should be when our fellow Americans are putting their lives at risk in a war. But Congress has made a poor start in other respects in performing its constitutional role. It failed to follow up when it authorized an unspecified use of force against Iraq last October if diplomacy did not work. It only halfheartedly debated the pros and cons of extending the United Nations inspections vs. going to war – in sharp contrast with the spirited, substantive debate in the British House of Commons.

Now that the president has, in effect, declared war, the lawmakers should exercise another of their constitutional powers, to provide for “the general welfare.” As the inevitable fog of war descends on the combat zone, they must monitor the conduct of the war, the structure of the peace and whatever plans may be made for future wars against other perceived enemies. The president, as commander in chief, conducts the war. But Congress also has a role, which goes far beyond the huge task of raising the money to pay for it. Here is a partial list of some of the war-related matters that merit continuing congressional attention:

. Protecting the rights of servicemen and women. For example, an old federal law about disability benefits prohibits adding them to military retirement pay. Wartime casualties require better treatment than that.

. Appraising whatever stocks of chemical or biological weapons are turned up as American and British forces occupy Iraq. If Saddam Hussein does not use them against the invading forces, he may no longer have them. He can hardly have been intimidated by American threats to try him as a war criminal. Likewise, Congress should join in appraising the current state of Iraq’s nuclear weapons program. If neither a flourishing nuclear weapons industry or stocks of other “weapons of mass destruction” are found, a prime justification for this war will seem faulty.

. After the expected victory, overseeing the reconstruction and rehabilitation of Iraq. Congress may have to intercede to ensure fair play in granting contracts for rebuilding seaports and other facilities. The word thus far is that the contracts will go only to U.S. firms and that competitive bidding will be avoided. Congress should guard against cronyism and exorbitant profits. It can further use this opportunity to rebuild relations with other nations by inviting their firms to bid on some of the work.

. Raise the money to pay for it all. Unlike the first Persian Gulf war, when so much Arab money flowed in that the United States is said to have turned a profit, this one is on us. The president’s $75 billion as the down payment was the best argument for delaying the administration’s mammoth tax-cut plan.

. Protect our civil liberties while joining the executive branch in protecting the national security. That means walking a fine line.

. Finally, monitor the course under the Bush administration’s National Security Strategy, which actually replaces international law. Its doctrine of preemptive war proclaims that any U.S. president at any time in the future can decide to attack any country, provided only that the president is satisfied the suspect country might at some point represent a direct threat to the United States. Iraq came first, but obvious future candidates are Iran, North Korea, and Syria. Congress may, in its wisdom, see fit to reclaim its constitutional right to declare war.