WASHINGTON — Six months after the Arab world erupted in a political firestorm, President Obama has been searching for ways to link the region’s historic transformation to the long-stymied peace negotiations between Israel and the Palestinians. It is far from clear how he can do that.

Mr. Obama will have a chance to reshape the debate on Thursday, when he delivers a major speech on the region at the State Department. The president plans to argue that the political upheaval raises the prospect for progress on all fronts, and will offer “some specific new ideas about U.S. policy toward the region,” the White House press secretary, Jay Carney, said Tuesday.

Officials said Mr. Obama was weighing whether to formally endorse Israel’s pre-1967 borders as the starting point for negotiations over a Palestinian state — a move that would be less a policy shift than a signal by the United States that it expected Israel to make concessions in pursuit of an agreement.

But several officials said the president did not plan to present an American blueprint for breaking the stalemate between the Israelis and Palestinians. In the absence of that, experts said, there is little he can do to draw the two sides closer, especially since the Arab upheaval has deepened the rift between them.