When planning began for this year's AIPAC conference, America's pro-Israel lobby could hardly have imagined the tumult now coursing through the Middle East.

The American Israel Public Affairs Committee gathering convenes beginning Sunday amid unprecedented regional changes that are bumping Arab-Israeli peace talks down the list of priorities and highlighting potential new threats to the Jewish state, analysts say.

Featuring keynote speeches by US President Barack Obama and Israeli Prime Minister Benjamin Netanyahu, the conference brings together some 10,000 students, powerbrokers, government and military officials, foreign ambassadors, analysts, and rabbis and other religious figures from across the United States and Israel.

And yet while US lawmakers from all political stripes make an annual pilgrimage of sorts to AIPAC to pledge their support for the state of Israel on a grand stage, it is the Arab world that is taking the spotlight in 2011.

In a short few months, the region including North Africa has been rocked by pro-democracy revolutions sweeping longstanding leaders from power in Tunisia and Israeli peace partner Egypt; civil war in Libya; deadly anti-regime unrest in Syria and Yemen; violent protests along Israel's border; and the killing by US forces of terror kingpin Osama bin Laden.

AIPAC is scrambling to grasp the magnitude of changes that have swept the Middle East this year, and assess exactly how they will affect Israel, its chance for peace and its all-important relationship with key ally the United States.

"It's a very different situation than in December... and dramatically so," a senior official in the pro-Israel lobbying community said this week.

A further development for AIPAC to digest when it convenes: the Palestinian Authority government of Mahmud Abbas has struck a high-stakes unity deal with Hamas, the rival Palestinian faction which Washington deems a terrorist group.

"The situation with Hamas has changed everything," the lobby community official said.

Yet broader developments abound, including revolt and unrest on Israel's doorstep.

"This is a tumultuous moment in the Middle East, with great hope and great promise, but also great uncertainty and perhaps great fear," Robert Satloff, who heads the Washington Institute for Near East Policy, said.

Israel's relations with the Palestinians is an urgent issue, he said, but the conventional idea of a peace process in the midst of regional convulsion "doesn't seem to be relevant in the current moment."

What is top priority, according to Satloff, is that the democratic changes in the region "proceed well and end positively."

Some analysts note that the popular revolts in Tunisia, Egypt, Libya, Syria and Yemen had little if anything to do with Israel -- yet AIPAC is watching those nations closely for the emergence of any potential new threats, including populist waves of anti-Israel sentiment.

In his speech Thursday on the Middle East, Obama spoke of "the extraordinary change taking place," and insisted that "the drive for a lasting peace that ends the (Arab-Israeli) conflict and resolves all claims is more urgent than ever."

But Mideast expert Khaled Elgindy, a Brookings Institution visiting fellow who advised the Palestinian team negotiating with Israelis between 2004 and 2009, was blunt about the Obama administration's eye on the region, saying the peace talks issue "is being kicked down the ladder."

What's drawing more attention, he said, is the Arab Spring, which Elgindy described as one of the "biggest game-changing moments in the region's history."

"I'm sure they (AIPAC) will be looking at the changes in the region," notably in Egypt, where president Hosni Mubarak, who demanded stability on his country's borders with Israel, was ousted in a populist revolt.

Also of increasing concern is Syria, whose embattled President Bashar al-Assad had also kept unrest to a minimum with Israel, but which the lobby official described as "this great unknown" now that Assad is facing mounting anti-regime protests and Washington has urged him to lead a transition.

"He's going, and we've got to deal with who comes next," the official said.

Marina Ottaway, director of the Middle East program at the Carnegie Endowment for International Peace, said the Arab Spring has been an "uncertain time" for AIPAC.

"They are not saying openly that they are against these transformations, but they are raising old issues," she said, particularly the fear that political transitions could be exploited by Islamic extremists who help install governments more hostile to Israel.

And so AIPAC will use its significant clout on Capitol Hill to burnish the US-Israel relationship, and pressure lawmakers to pledge that they have Israel's back.

With senators and congressmen beating a path to AIPAC's meeting, Ottaway said it's clear the group holds huge sway in Congress.

"The pro-Israel lobby is the only lobby that likes to play down its own importance," she said. "Usually, lobbyists do the opposite."