Palestinians say it will trigger the biggest West Bank demonstrations in years. Israelis are bracing for another intifada.

A month before a potentially historic United Nations showdown over Palestinian statehood, the two sides are mobilizing for the possibility of mass street protests that some fear could spiral into a violent uprising.

As Palestinian leaders rally West Bank residents on Facebook and activists prepare campaigns against Jewish settlements and military checkpoints, Israel's Defense Ministry has spent about $22 million on new riot gear and police have canceled September vacations.

"There will be activities everywhere — against the wall [Israel's separation barrier], against the settlements and against the occupation," said Wasel Abu Yousef, who heads the Palestine Liberation Front, a faction of the Palestine Liberation Organization. "We want to escalate all popular protests."

Palestinian officials say they are committed to keeping demonstrations nonviolent. But given the history of bloody clashes between Israelis and Palestinians, as well as the powerful example of uprisings sweeping through neighboring Arab nations, Israelis are preparing for the worst, including calling up military reservists and making plans for emergency evacuations of settlements and an increased military presence in Palestinian-administered regions of the West Bank.

"Our forces are training for a variety of scenarios," Israel Defense Forces spokeswoman Lt. Col. Avital Leibovitz said. "The phenomenon of violence and riots is not new for us. But if something severe happens, it's going to be a big challenge because it will involve civilians."

To prepare, the military is stockpiling tear gas dispensers, rubber bullets, stun grenades and so-called skunk water cannons, which spray a foul-smelling liquid and have been used to disperse weekly Palestinian protests against the separation barrier in Bilin and other villages.

Both sides are mindful that the international community will be watching closely, and both insist they will work to keep confrontations under control.

This month Palestinian leaders — from Palestinian Authority President Mahmoud Abbas to imprisoned uprising activist Marwan Barghouti — began stepping up their public calls for street demonstrations next month to demonstrate impatience over the lack of a Palestinian state.

A new Facebook page launched by the Palestinian Authority seeks to organize and motivate young people to support a Sept. 20 demonstration, dubbed Palestine 194 to signify Palestinians' hopes of becoming the 194th state to be recognized by the U.N. General Assembly. That decision would be made later in the month.

Meanwhile, activist groups are meeting in Palestinian villages and refugee camps to map out a schedule for smaller protests in the coming weeks to build momentum in the run-up to the September decision.

Military officials are particularly worried about large-scale demonstrations attempting to swarm into Jewish settlements in the West Bank or break through checkpoints into Jerusalem.

One military officer told the newspaper Haaretz that mass protests like the kind seen in Arab nations in recent months would be "unstoppable. Such a great number of determined people cannot be stopped by tear gas and rubber bullets."

In the spring, Israeli border guards got a sample of what might be in store when hundreds of pro-Palestinian protesters tried to break across the borders from Syria and Lebanon. Soldiers opened fire, killing more than two dozen people in two separate incidents, according to Syrian officials.

Israeli Foreign Minister Avigdor Lieberman said he would hold Palestinians responsible if protests turned bloody. "When you prepare a demonstration in which tens of thousands will storm the Kalandia checkpoint," he said, speaking of the crossing from the Palestinian city of Ramallah into Jerusalem, "everyone can just imagine what would happen if 30,000 or 40,000 people try to forcefully enter Israel. How are soldiers and officers supposed to react?"

Palestinian officials said Israel was exaggerating the potential threat.

"All indications show that we will have only peaceful demonstrations," said Maj. Gen. Adnan Damiri, a spokesman for the Palestinian security forces. "We are not nervous nor on alert. The Israelis have their reasons and motives. They want to show to the world that by going to the U.N. we are taking this region and the world to war. We do not see it the same way."

Nevertheless, he said, Palestinian forces would prevent demonstrations from getting out of hand. "We will not allow any violence or attempts by anyone to change the peaceful course of the protests," he said.

Some Palestinians are skeptical that large-scale demonstrations can be sustained in the West Bank, noting that recent efforts to organize the kind of popular protests seen in other Arab nations have faltered amid Palestinian apathy.

"We tried the Facebook page approach, but it's not working the same way here that it did in Egypt," said Nancy Sadiq, a leader of the Palestinian Youth Council, a new coalition of activist groups based in Ramallah. Attempts over the summer to organize West Bank protests drew only a few people, she said.

"We still don't have a strategy for nonviolent resistance," Sadiq said. "We need a unified vision. Otherwise, I don't think it will happen."

Recent posts on pro-Palestinian Facebook pages, such as "September Is Our Anticipated Date" and "Third Intifada," focus more on the violence in Syria and Libya than on the Palestinians' own September initiative.

In the Gaza Strip, where the Palestinian militant group Hamas has voiced skepticism about the usefulness of the upcoming U.N. initiative, youth activists say they are more concerned about completing a pending reconciliation agreement between Hamas, which controls Gaza, and the Fatah faction, which is spearheading the U.N. drive.

"The main goal should be to achieve unity, not to go to the U.N. to ask the world to give us a state that has no resources," said Mohammed Sheikh Yossef, a youth leader in Gaza.

Others, however, predicted that the September initiative would be the trigger that finally galvanizes Palestinians into large protests, particularly if the U.N. campaign fails to achieve what Palestinians are seeking.

"There is a different atmosphere because of September," said Jonathan Pollak, an Israeli activist who helps organize weekly protests against the separation barrier. "Everyone agrees this could be the catalyst for mobilizing people."