Want to know whether the White House has any real strategy to stabilize Iraq?

Then pay attention to what happens - or doesn't happen - at a crucial meeting May 3 and 4 in the Egyptian resort of Sharm el Sheikh.

The event is a regional conference of leaders from Iraq and its neighbors that will be attended by Condoleezza Rice and, maybe, by Iranian Foreign Minister Manouchehr Mottaki. The reason the meeting is so important: The American troop surge is only a tactic, which can't work unless it fits into a broader regional strategy.

Such a strategy would require determined U.S. diplomacy to convince Iraq's neighbors to help stabilize the country rather than arm its militias. It would also require a frank U.S. dialogue with Tehran.

There's no sign yet of White House willingness to put full support behind the broad regional strategy that's needed. President Bush rebuffed the call by the bipartisan Baker-Hamilton Study Group report for just such "a robust diplomatic effort."

So I asked one of the State Department's most talented diplomats, Undersecretary of State Nicholas Burns - Rice's point man on Iran - whether the Sharm conference was just for show. He insisted that wasn't so, in an interview on the State Department's hushed and paneled seventh floor.

"We crossed some bridges to decide to have this conference [whose first, lower-level meeting took place in Baghdad on March 10]. We've now agreed to sit down with the Syrians and Iranians at the table . . . We actually would like to see if this conference . . . could be helpful to . . . stabilizing Iraq."

So what is the conference's goal? "Our number-one issue . . . will be reducing the flow of fighters across the border of the neighbors into Iraq," Burns said. U.S. officials also want to discuss how the neighbors could give Iraq more economic, political and humanitarian support.

Could the goals of the conference be broadened? Neither Sunni Arab states such as Saudi Arabia nor Shiite Iran want Iraq to collapse, lest that draw them into a sectarian proxy war over Iraq's corpse. Yet that seems to be where the neighbors are heading.

Could not an expanded regional conference work to set up new security rules for the region, requiring Iran not to meddle in Lebanon or Gulf states and Sunni Arab states to stop aiding Iraq's Sunni insurgents? Might it not imitate the 2001 Bonn conference, where the United States and Iran cooperated on a political settlement for Afghanistan?

Burns was quick to downplay a comparison between next week's confab and Bonn. "We're thinking hard now about what our realistic ambitions should be," he said. That depends a lot on "the degree of seriousness or not that the Iranians give to this" and whether Iran sends a "senior interlocutor" to Sharm.

Which brings us to the crux of the problem: how to deal with Iran.

At the Bonn conference, Iran and the United States acted on their shared interest in stabilizing Afghanistan. The two countries share similar interests in Iraq, where Tehran is the only neighbor that fully supports the Shiite-led government against Sunni insurgents. Yet Washington and Tehran have been unable to cooperate.

Washington deplores Tehran's suspect nuclear program and aid to terrorist groups, and Tehran suspects America wants to use Iraq as a base to unseat its regime. So Iran helps radical Shiite militias to bleed U.S. troops.

Right now it isn't even clear whether Iran will send a high-level official to the Sharm meeting. Tehran first wants the release of five Iranians arrested by U.S. forces in the Iraqi Kurdish town of Erbil.

Once the Sharm talks start, "We wouldn't exclude bilateral contacts [with Iranians] as a possibility," Burns said. "But that's not the focus of what we are doing."

U.S. policy toward Iran is focused on "blocking, containing, pushing back Iranian attempts to expand its power base in the Middle East because we think it's . . . going to be against our interests and most of the countries involved," he said.

What struck me about my conversation with Burns is that the State Department understands the crucial role of diplomacy for Iraq. But it's far from clear the White House will approve the forceful diplomatic drive that is needed. Other sources tell me that Vice President Cheney has been pushing back against the idea of serious dialogue with Tehran in a regional context.

Containment of Iran may be necessary on certain issues, including the nuclear question, but cooperation with Iran is essential to save Iraq. Without a broad diplomatic strategy for the region, the surge is headed nowhere. Without a coherent White House vision behind it, the Sharm meeting can't achieve what Iraq needs.

Contact columnist Trudy Rubin at 215-854-5823 or trubin@phillynews.com. Read her recent work at http://go.philly.com/trudyrubin.