On Aug. 7, 1974, Sen. Hugh Scott of Pennsylvania went to the White House with two other Republicans to tell Richard Nixon his position on Watergate was hopeless. Two days later Nixon resigned.

The time has come for another Hugh Scott moment. No, I’m not yet suggesting Republicans march to the White House and tell George W. Bush to return to Texas.

But if we and the Iraqis are to be saved from the consequences of Bush’s follies, only Republicans can do it. Twelve good men and women are needed, or perhaps 17 (which would enable a bipartisan proposal to survive a veto). The senators need to tell Bush he can’t wait until September, when Gen. David Petraeus and Ambassador Ryan Crocker deliver their next “snapshot.”

They should deliver a message like this:

“Mr. President, as the polls show, the American public no longer believes in the Iraq war. Our generals say the solution must be political and our goal is to hand over security to Iraqis. Yet the public can see that the Iraqi government is divided by sect and ethnicity, as are Iraqi security forces. If Iraqis can’t get together, voters ask, how can our military ever hand over?

“We Republicans must confront that question. Otherwise voters will demand a speedy troop exit that will lead to greater Iraqi bloodshed, strengthen Islamists and destabilize the whole region. Unless Iraqis can reconcile, the civil war is bound to get worse even if you hold firm until 2009.

“So if Iraqis can’t help themselves, you must pursue the one strategy that might advance political reconciliation. You should endorse a new international diplomatic offensive in the Middle East – under United Nations auspices – to help stabilize Iraq and the entire region. All your remaining political capital must go into this effort.

“This is the path endorsed by the Baker-Hamilton Iraq Study Group, and it could win bipartisan Senate backing. But it would take a wholehearted and public commitment by you.”

Would Bush listen to such a request? And, at this point, could international diplomacy really check Iraq’s turmoil? The answer to the first is iffy, but I believe the answer to the second is yes.

To convince Bush, Republicans must first recognize that the current Bush strategy is a trap for them and the country. I don’t just mean a political trap in the 2008 elections. I mean a strategic dead end.

Yes, we are making military progress in Iraq. Sunni tribal leaders have turned against al-Qaida in Iraq, as have some groups of Sunni insurgents, who are now cooperating with U.S. troops.

But we still have no way to build on these gains. Many of the Sunni groups helping us against al-Qaida in Iraq are itching to attack Shiites. If U.S. troops pull back, Iraq’s civil war is likely to explode further, aided by her neighbors. Al-Qaida in Iraq will come roaring back into Sunni areas.

Yet U.S. troops can’t stay on in such numbers – and not just for political reasons. Every military commander I spoke with in Iraq in June brought up the untenable burden being placed on the Marines and the Army; come spring 2008, those troop levels must come down.

These realities give Hugh Scott Republicans the leverage to press Bush for a new diplomatic strategy that aims to diminish the sectarian violence in Iraq. I mean a serious, well-prepared diplomatic effort, unlike last week’s half-baked call for talks on the Palestinian issue.

This initiative would seek to establish a new security framework for the entire Mideast, one that dissuades Iraq’s neighbors from fighting a religious war by proxy inside Iraq. A prime goal would be to reassure Sunni Arab countries that Iran would not stir up Shiites throughout the region. Another goal would be to reassure Tehran that Saudi Arabia will not encourage Iraqi Sunnis to try to seize power from Iraq’s Shiite majority.

If Iraq’s Sunni and Shiite neighbors reached a modus vivendi, they would be more willing to encourage their Iraqi proxies to reconcile. That, in turn, would enable U.S. forces to draw down.

Such a diplomatic effort would involve a major U.S. political commitment, and the appointment of a top-flight U.S. negotiator, with the cachet of a James Baker. It would also require serious U.S. engagement with Tehran and Damascus, which this administration has long avoided.

Several Senate Republicans have endorsed this approach. The U.S. ambassador to the United Nations Zalmay Khalilzad (previously ambassador to Baghdad) has hinted at some American interest.

But such a diplomatic process can go forward only if Bush backs it without equivocation. And only the heaviest pressure from Republicans is likely to convince him. If they go this route, Republican statesmen will have to decide what to do if the president rebuffs them. A Hugh Scott moment means pulling out all stops to make the president see the light.

– Trudy Rubin is a columnist and editorial board member for the Philadelphia Inquirer.