President George W. Bush announced plans to raise the number of troops in Iraq last week, when he revealed his new strategy to pacify that troubled country. Many Democratic lawmakers support exactly the opposite approach, preferring withdrawal to escalation.

Senior Fellow  Kevin A. Hassett

Turning up the volume for the more strident anti-war Democrats, former Senator and recently announced 2008 presidential candidate John Edwards said in a "prebuttal" to Bush's speech, "The new Congress must intercede to stop Bush from stubbornly sticking to the same failed course in Iraq and refuse to authorize funding for an escalation of troops."

Edwards's call to Congress is reminiscent of an action taken during the Vietnam era by Senator William Fulbright. Fulbright sought to limit funding for the Vietnam War through amendments to spending bills. The first such bill was the Laos-Thailand amendment to the Defense Appropriations bill of 1970. It prohibited the U.S. military from using money to put troops in Laos and Thailand.

Historians believe these actions hindered President Richard Nixon's Vietnam strategy, and helped ultimately to bring the war to an end.

Clearly alluding to this experience, Massachusetts Democratic Senator Ted Kennedy told the New York Times last week that, "we have in previous circumstances impacted troop levels. We did it in Lebanon, in 1983, and we did it in Vietnam. This is the power of the purse."

More Spending

With President Bush seeking to escalate the war, additional spending that must be approved by Congress will be necessary. As soon as next month, Congress will consider a supplemental bill for as much as $100 billion, covering more than $2 billion in weekly spending on the war.

Will that set up a face-off that changes the course of the Iraq war as Edwards, Kennedy and their Democratic allies hope?

My colleague at the American Enterprise Institute, John Fortier, a political scientist with expertise in constitutional law thinks that such a course is unlikely.

"Even if Congress cut off funding for the war, that might not resolve the issue," he told me last week. "President Bush might well argue that Congress had already authorized the war and that cutting off funds would undercut his constitutional commander-in-chief power. The Supreme Court would be reluctant to step in and resolve this constitutional clash."

Constitution Showdown

In other words, Nixon might have chosen to ignore the Laos and Thailand amendment and been able to prosecute the war as he saw fit. Presumably, he avoided such a path for fear of negative publicity.

It seems unlikely that Bush would be similarly cautious about publicity. So an attempt by Congress to constrain him could set off an historic confrontation.

This is a tricky issue. The power of the purse conflicts with the president's role as commander-in-chief. If Bush decided to send as many troops as he feels necessary, then the courts would probably take a very long time to stop him. Recognizing this, it seems very unlikely that Democrats would cut off funds for the war.

They do, however, have another alternative that may actually be more effective at increasing pressure on those who support the president. Rather than hold back money for the war, they could require the president to fund it.

No Spending Cuts

Up until now, expenditures on Iraq have been passed in supplemental spending bills that have existed far outside the normal budget process. At the same time, the war's costs haven't been offset by spending cuts elsewhere, or by tax increases. The war has been financed by deficit spending.

This has annoyed fiscal conservatives of both parties. For example, Senator Judd Gregg, Republican of New Hampshire, said in a speech on the Senate floor last week that that the Defense Department needs to clean up its budget act.

"They need to structure the budget that they send up here so that if they want to have a separate account for the war fighting, fine," he said. "I can understand that. But it should be a separate budget, it shouldn't be an emergency budget. And it should go through the authorizing and the appropriating process."

If Democrats support this effort to include the Iraq war in the budget, and require any escalation to be funded under their new pay-as-you-go rules, then taxes will have to be increased (or spending cut elsewhere) to fund the Iraq war.

The war is so expensive that paying for it without borrowing would be as difficult a fiscal policy lift as can be imagined, and doing so would negate the Bush tax cuts.

My guess is that those opposed to the war will huff and puff about the escalation, but do nothing to impede it. But if they do decide to get more aggressive, they may well try to force Republicans to accept tax increases as a cost of escalating the troop presence in Iraq.

Kevin A. Hassett is a senior fellow and director of economic policy studies at AEI.