The pen that launched the landmark reconciliation between Fatah and Hamas this week is likely to have a mightier impact on U.S. policy toward the Israeli-Palestinian conflict than the bullet that killed Osama bin Laden.

Could President Barack Obama try to capitalize on the boost he’s getting from bin Laden’s death to advance the stalled peace process? Some experts say yes. But most say that the killing of America’s Public Enemy No. 1 will matter less to peacemaking than the willingness of the two sides to start talking again.

Palestinian Authority President Mahmoud Abbas (left) and Prime Minister Ismail Haniyeh of Hamas at a special session of parliament in Gaza City in 2007. photo/ap/hatem moussa

“The only problem for the president, who doubtless remains as obsessed with the peace process as he always has been, is that the Hamas-Fatah deal will seriously complicate matters,” said Danielle Pletka, a vice president at the American Enterprise Institute and a former top Senate aide who dealt with foreign policy.

The new Palestinian unity government — which Israeli Prime Minister Benjamin Netanyahu called a “big prize for terrorism” — will make it hard for Obama to use any additional leverage he has from bin Laden’s killing to push for Israeli-Palestinian peace, she said.

Palestinian Authority President Mahmoud Abbas favors a negotiated peace with Israel, while Hamas refuses to accept Israel’s existence.

Netanyahu, who was planning a major announcement on the Israeli-Palestinian issue in his address to Congress later this month, spent this week criticizing the pact, which makes no mention of Israel.

The agreement “must concern not only every Israeli, but all those in the world who aspire to see peace between us and our Palestinian neighbors,” Netanyahu said May 2. “Peace is possible only with those who want to live in peace alongside us and not with those who want to destroy us.”

Abbas’ Fatah party and Hamas, along with several other Palestinian factions, formally signed the Egypt-brokered unity pact May 4, setting off ecstatic celebrations in the Palestinian territories.

Under the agreement, the rival factions will form a transitional government with presidential and legislative elections in a year. Abbas said he will not be a candidate for president.

A previous unity arrangement collapsed into civil war in June 2007. In five days of fighting, Hamas overran the Gaza Strip, leaving Abbas’ P.A. in charge of the West Bank. Reconciliation is said to be essential for Palestinian dreams to establish a state in the two areas.

Since news of the deal broke last week, Netanyahu has warned Abbas that Israel won’t deal with a government that includes Hamas. “How is it possible,” he asked, “to achieve peace with a government, half of which calls for the destruction of the State of Israel and even praises the arch-murderer Osama bin Laden?”

Netanyahu has the support of a long list of Congress members who say there can be no more talk of moderates vs. terrorists with Hamas and Fatah in bed together.

“The [pact] means that a foreign terrorist organization [Hamas] which has called for the destruction of Israel will be part of the Palestinian Authority government,” Rep. Ileana Ros-Lehtinen (R-Fla.), the chairwoman of the House Foreign Affairs Committee, said in a statement. “U.S. taxpayer funds should not and must not be used to support those who threaten U.S. security, our interests, and our vital ally, Israel.”

The administration had hoped to provide more than $500 million in aid programs for Palestinians next year, the Associated Press reported.

All of this might lead to yet another Congress vs. White House rift, as the Obama administration, while expressing its unhappiness with the compromise, reportedly has not ruled out the prospect of supporting a reconstituted P.A. in which Hamas plays some role.

Israel this week said it will delay a routine transfer of $88 million in tax proceeds collected for the P.A., pending proof that the money will not go to Hamas. Israel collects some $1 billion to $1.4 billion in taxes annually for the P.A. as part of the 1993 Oslo Accord, Ynetnews.com reported.

“The burden of proof lies with the Palestinian Authority to show that not even one shekel is given to Hamas and funds terror,” Israel Finance Minister Yuval Steinitz told Israel’s Army Radio. “Is it certain that none of the money will be transferred to a terror organization to purchase missiles and rockets?”

David Makovsky, a senior analyst at the Washington Institute for Near East Policy, said the Hamas-Fatah deal takes pressure to forge a deal off Netanyahu.

“What Abbas has done in a stroke of the pen has helped win domestic peace, but he’s also helped Netanyahu,” Makovsky said. “It will be hard to pressure Netanyahu when there’s a power-sharing deal with Hamas. He’s extricated Netanyahu from the pressure.”

“Abbas has given Netanyahu a gift that will not stop giving,” added Aaron David Miller, a scholar at the Woodrow Wilson Center who has worked as a negotiator for the Clinton and both Bush administrations.

Israeli Defense Minister Ehud Barak told U.N. Secretary-General Ban Ki-moon over the weekend that the United Nations should make a new Palestinian unity government recognize Israel as a condition for cooperating with the government, Reuters reported.

In a message to Israel after the pact was signed, Abbas said: “We reject blackmail and it is no longer possible for us to accept the occupation of Palestinian land.”

The Associated Press contributed to this report.