WASHINGTON - Israel's military onslaught against Hamas will probably make it harder for President-elect Barack Obama to fulfill a campaign pledge of early and vigorous Mideast peacemaking, and the pre-inauguration timing might frustrate any effort he plans to establish new footing among Arab partners.

Obama's foreign-policy advisers are lying low out of deference to President Bush and are refusing to speak to the implications of Israel's operation in the Gaza Strip. But transition aides are being briefed by Bush administration officials and are quietly pondering its effects.

Secretary of State Condoleezza Rice has had "direct conversations" about the situation with both Obama and her designated successor, Sen. Hillary Rodham Clinton, the State Department has said. An Obama aide said the president-elect would be discussing the matter with Clinton and his incoming national security adviser, retired Gen. James Jones.

Analysts believe Israel timed the air attacks to prevent the situation in Gaza from becoming Obama's first major foreign-policy crisis when he takes office Jan. 20, as well as for domestic political reasons. But they also think the offensive against Hamas may undermine any short-term initiative Obama's administration might try.

"The Israelis don't want to greet the president-elect with this problem as the first thing when he enters the Oval Office," said Steven Cook, senior fellow for Middle Eastern studies at the Council on Foreign Relations. Yet it "clearly complicates any effort to engage in a vigorous diplomatic effort."

Another council fellow, Dan Senor, agreed, saying Israel had calculated that it would have to act quickly before Obama moves into the White House or else wait months.

"The last thing [they] wanted was when the president-elect is sworn in that the first thing on his welcome mat is this incursion into Gaza," said Senor, a former Bush administration communications official.

"It wouldn't be good for Israel," he said. "It wouldn't be good for President Obama's new administration. In a sense, it wasn't in anybody's interest."

Israel can count on firm support from the Bush administration for the Gaza operation, despite broad condemnation in the Arab world and rising calls elsewhere for Israel to pull back in the face of mounting civilian casualties.

But a primary risk, according to Cook and others, is that the offensive in Gaza will further undermine already weakened Palestinian Authority President Mahmoud Abbas, who controls only the West Bank and has little to show from more than a year of negotiations with the Israelis that began in 2007 at a peace conference in Annapolis, Md.

Another is inflamed tensions against Israel and its chief ally, the United States, that could undermine high hopes the Arab world has for a change in U.S. course in the region under Obama, they said.

Rice also has reached out to more than a dozen foreign leaders and senior officials in a bid to prevent the situation from spiraling out of control and to keep the Annapolis process, which was recently enshrined as "irreversible" at her urging by the U.N. Security Council, at the forefront of the peace push.

Clinton and Jones, who has been supervising Palestinian security arrangements in the West Bank, are familiar with the intricacies of Israeli-Palestinian peacemaking. As New York's junior senator, Clinton has strongly supported Israel, a history that may help her with Israelis and hurt her among Arab leaders.

The operation in Gaza has at the very least muted Rice's effort, which is also complicated by the transition in Washington and the coming Israeli elections, in which all candidates are eager to appear tough on Palestinian extremists.

Abbas also has said he will call general elections soon, signaling he is ready for a new showdown with Hamas.

Hamas, which wrested control of Gaza from Abbas 18 months ago, contends that his term as president ends Jan. 8. Abbas initially said he had another year, but polls indicate most Palestinians disagree with him.

A call for elections appears to be the only way for Abbas to retain legitimacy. However, it remains unclear whether he actually intends to hold them or just plans to call for a vote as a tactical move.

It is also not certain whether elections would unify the Palestinians or deepen the divisions.