As the “Rummy Must Go” chorus grows in rank and numbers, it’s beginning to feel like Secretary of Defense Donald Rumsfeld’s days are numbered. Three years into the war in Iraq, American casualties are back on the upswing, the fledgling government is stalled and car bombs and assassinations are wreaking havoc on civilians. The war is not yet a failure, but the prospects for victory, at least the total victory President Bush and Rumsfeld initially promised, are nil.

In short, despite Bush’s praise for him Friday, there is no compelling argument for keeping Rumsfeld. He fought the war the way he wanted, against the advice of many commanders, and it hasn’t worked out. Military rules of accountability, not to mention election-year jockeying, could dictate a change. But even if Bush were to do an about-face and boot him, there are two questions that everyone, including the six retired generals demanding Rumsfeld’s firing, must answer before the ax falls.

First, what would be the benefits of a new secretary?

Second, how would such a dramatic firing affect the morale of our troops in Iraq and Afghanistan?

As to the benefits, it’s hard to see what they would be unless American policies, military and political, also change. The issue is not who, but what. What are our goals and what are we willing to do to achieve them?

Although Bush has lowered his sights, promising our troops will leave when Iraqis can take their place, even those diminished aims seem out of reach. It’s not clear how a new secretary alone would make a difference.

Consider one of the key criticisms of Rumsfeld: that he was so intent on modernizing and slimming the armed forces that he never put enough troops on the ground. While military planners had for years estimated that it would take up to 500,000 troops to occupy Iraq after Saddam was toppled, coalition forces have maxed out at 180,000, including 150,000 Americans. Retired Marine Gen. Anthony Zinni, for example, one of those now condemning Rumsfeld, recently said more troops would have snuffed out the insurgency before it began. When I asked Zinni whether more troops also would have led to more American casualties, he said no, that he believed a stronger presence would have actually prevented many of our losses.

Those are intriguing points, but even if Bush and a new secretary now adopted that thinking, it may be too late to act. A huge increase in our troop levels would not be welcomed by Iraqis. And here at home, the war is so unpopular that Bush and the GOP would be punished in the November elections if they tried to send more soldiers into battle.

As for the troop morale issue, virtually all reports, official and anecdotal, say it remains high. That is a credit to the character of our forces and their training. But how would they react if Rumsfeld, their boss, were booted because of the results? We can’t know for sure, but it’s hard to fathom how their morale or performance would improve. Most likely, an element of doubt would surface, about themselves and their mission. Doubt on the battlefield can be fatal.

Rumsfeld has said twice that he offered to quit, but that Bush refused to accept his resignation. Perhaps the third time will be the charm. Fair enough.

And then what?