WASHINGTON - Pouring rain did not prevent more than 6,000 people from attending Sunday's opening of the annual AIPAC conference in Washington, which is considered one of the city's 10 biggest political and media events.

Politicians, academics, Jewish community activists and more than 1,000 college students came to participate in the dozens of panels and workshops hosted by the American Israel Public Affairs Committee, a leading pro-Israel lobby. The topics ranged from "lobbying for beginners" to various scenarios for both the future of U.S.-Israel relations and developments in the Middle East.

Because this year's conference coincided with a new administration in Israel, there were more former decision-makers than current ones present. However, President Shimon Peres will attend Monday's conference session, which will focus on the Iranian nuclear threat, and Prime Minister Benjamin Netanyahu will address the gathering by video tonight.

Neither U.S. President Barack Obama nor Secretary of State Hillary Clinton - both of whom attended last year's AIPAC conference as presidential candidates - will address the gathering this year. Instead, the U.S. administration will be represented by White House Chief of Staff Rahm Emanuel. Several leading congressmen will also attend.

Michael Oren, the noted historian who is slated to be the next Israeli ambassador to the U.S., appeared Sunday on a panel about Israel's "cold peace" with Egypt and Jordan. But he opened his remarks by stressing that since the cabinet had yet to formally approve his appointment as ambassador, he was addressing the gathering strictly as an academic.

The hottest topic in the corridors was Iran's nuclear program and how Israel would respond, and this also got plenty of attention in the official program.

"Israel will not allow Iran to obtain nuclear weapons," Oren told lobbyists.

Oren, a noted historian, was quoted as saying that Israel would not remain passive while a regime that has sworn to wipe it off the map acquired the means to do this, referring to comments made by Iranian President Mahmoud Ahmadinejad.

At another panel discussion yesterday, former deputy defense minister Ephraim Sneh bluntly told participants that time was running out: Based on what Israel knows about Iran's progress, he said, the deadline for a decision is now.

Israel, he added, has an "operational solution" to this program that it can implement on its own, without the permission or support of any other country. However, since any Israeli military action would surely provoke Iranian retaliation, military action is a last resort, he said.

Nevertheless, he stressed, military action is better than allowing Iran to have nuclear weapons, since should Iran acquire nuclear weapons, this would negatively affect Israel in seven different ways: Immigration would dry up; parents would encourage their children to emigrate; investment in Israel would drop significantly; Middle East moderates would become more extreme, making a peace deal with Syria much less likely, for instance; terrorists would become bolder, thanks to having a patron with nuclear arms; Israeli decision-making would become more timid, for fear of provoking Iran; and a nuclear arms race would erupt throughout the Middle East. There are rumors, he noted, that Saudi Arabia has already made a deal with Pakistan, under which the Saudis would buy the bomb from their fellow Sunni Muslims in Islamabad the minute Shi'ite Iran acquires nuclear weapons. And Egypt would certainly not be far behind.

Asked about the likelihood that Russia and China would agree to impose serious sanctions on Iran, Sneh said he saw no chance whatsoever of this happening. But even if it did, he added, Iran could find other sources of fuel and spare parts for its reactors.