Presidents and prime ministers from major countries around the world will gather in Washington, D.C., in two weeks to begin heated negotiations over the shape of global financial regulation as they scramble to avoid a deep worldwide recession and restore confidence in markets.

Key European allies are pushing for broad new roles for international organizations, empowering them to monitor everything from the global derivatives trade to the way major banks are regulated across borders. But the Bush administration has signaled reluctance to go that far. In the past, it has resisted similar proposals as potentially co-opting the independence of the U.S. financial system or compromising free markets.

Some economists and policymakers say the summit could launch important reforms. Others predict it could turn into an economic tower of Babel, with weak political leaders promoting solutions fundamentally at odds with one another. And if leaders cannot bridge their differences, they could risk another bout of financial disarray.

There are also differences of opinion on the issue of timing. French President Nicolas Sarkozy, who pressed for the 20-nation summit, says it must produce concrete and immediate results. However, the host, President Bush, is a lame duck who says the meeting will be "the first in a series" and should focus on principles even though "the specific solutions pursued by every country may not be the same." Emerging proposals to sharpen existing regulatory tools appear to conflict with plans to create entirely new ones.

What is clear is that expectations for the summit among many observers are high.