The Associated Press

By BARRY SCHWEID

WASHINGTON (AP) — The next president would be wise to make contingency plans for a military attack against Iran, but even a successful strike might not stop Tehran's development of nuclear weapons, a bipartisan study group has concluded.

Intensified diplomacy and tougher economic sanctions aimed at Iran's oil and gas industries are more likely to be productive, said the forthcoming report by the Bipartisan Policy Center, prepared under the guidance of former Sens. Daniel Coats, R-Ind., and Charles Robb, D-Va.

"A military strike is a feasible option and must remain a last resort to retard Iran's nuclear development," the report said.

The next president could conclude that the risks of a military strike are outweighed by the dangers of a nuclear-armed Iran dominating the Persian Gulf and Iran possibly acting to eradicate Israel, the report said.

The U.S. military is capable of launching a devastating strike on Iran's nuclear and military infrastructure, probably a more decisive one than the Iranian leadership realizes, the study group said.

And it could set back significantly Iran's nuclear program, the report said.

"However, unless sustained by repeated strikes against rebuilt or newly discovered sites over a period of years, military action alone is likely only to delay Iranian nuclear development while entailing risks of retaliation ... which could quickly escalate to full-scale war."

Any U.S. military strike also would run a number of risks, among them rallying Iranians around their "unstable and ideologically extreme regime" and triggering widescale Hezbollah and Hamas rocket attacks against Israel, the report said.

While a successful bombing campaign would slow Iranian nuclear development, Iran would retain its nuclear knowhow. The United States would have to be prepared to attack previously undiscovered nuclear sites to ensure Iran does not resurrect its military nuclead program, the report said.

Iran's nuclear development may pose the most significant strategic threat to the United States during the next administration, threatening the Persian Gulf region and its vast energy resources, spark nuclear proliferation through the Middle East and destabilize Saudi Arabia and other nations in the region, the report said.

The Bush administration has kept the military option on the table while saying it would talk to Iran under certain conditions.

Republican candidate John McCain's approach is similar. He emphasizes retaining the military option. Democratic candidate Barack Obama would consider unconditional talks with Iran. He has not ruled out a military option.

By Louis Charbonneau

UNITED NATIONS (Reuters) - Republican vice presidential candidate Sarah Palin will not speak at a rally against the president of Iran next week and White House hopeful Sen. John McCain said on Thursday organizers had withdrawn her invitation under pressure from their Democratic rivals.

A group of Jewish organizations had said both Palin and Sen. Hillary Clinton would speak at the protest near the United Nations on Monday against Iranian President Mahmoud Ahmadinejad, who has said Israel should be wiped off the map.

But a senior Clinton adviser said the New York Democrat canceled her appearance after learning Palin was scheduled to address demonstrators as well.

"Gov. Palin was pleased to accept an invitation to address this rally and show her resolve on this grave national security issue, regrettably that invitation has since been withdrawn under pressure from Democratic partisans," McCain said in a statement.

"We stand shoulder to shoulder with Republicans, Democrats and independents alike to oppose Ahmadinejad's goal of a nuclear armed Iran," he said. "Sen. Obama's campaign had the opportunity to join us. Sen. Obama chose politics rather than the national interest."

Clinton decided not to attend because she did not want to take part in a "partisan political event," her aide said. She lost a hard-fought battle for her party's nomination to Sen. Barack Obama, but is now supporting the Democratic nominee for the Nov. 4 U.S. presidential election.

Among those scheduled to attend the protest are Nobel laureate Elie Wiesel and the speaker of Israel's parliament Dalia Itzik, publicist Casey Sanders said on behalf of the organizers.

"In order to keep the focus on Iranian threats and to ensure that this critical message not be obscured, the organizers of the rally have decided not to have any American political personalities appear," she said.

U.N. officials have also said it was possible McCain and Palin might show up on the sidelines of the opening of the U.N. General Assembly on Tuesday.

This would give Palin a chance meet a few world leaders on the day President George W. Bush and one of his main foes, Iranian President Ahmadinejad, address the 192 U.N. member states.

Although Palin, 44, has brought new energy to the McCain campaign and helped narrow Obama's lead in opinion polls before the election, Democrats say the mother of five lacks the foreign policy experience a vice president should have.

Iran denies Western allegations that it is seeking atomic weapons, but has refused to suspend sensitive parts of its nuclear program that could be used to make atom bomb fuel.