Deepening economic strife in the US could lead to civil unrest and violence that would require military intervention, warns a new report from the US Army War College.

"Widespread civil violence inside the United States would force the defense establishment to reorient priorities in extremis to defend basic domestic order and human security," writes Nathan Freier, a 20-year Army veteran and visiting professor at the college.

A copy of the 44-page report, "Known Unknowns: Unconventional 'Strategic Shocks' in Defense Strategy Development," can be downloaded here. Freier notes that his report expresses only his own views and does not represent US policy, but it's certain that his recommendations have come before at least some Defense Department officials.

The author warns potential causes for such civil unrest could include another terrorist attack, "unforeseen economic collapse, loss of functioning political and legal order, purposeful domestic resistance or insurgency, pervasive public health emergencies, and catastrophic natural and human disasters." The situation could deteriorate to the point where military intervention was required, he argues.

"Under these conditions and at their most violent extreme," he concludes, "civilian authorities, on advice of the defense establishment, would need to rapidly determine the parameters defining the legitimate use of military force inside the United States."

While the scenario presented is "likely not an immediate prospect," Freier concedes, it deserves consideration. Prior to 9/11, no one in the defense establishment would have envisioned a plot to topple skyscrapers with airliners, and the military should not be caught so off-guard again, he says.

To the extent events like this involve organized violence against local, state, and national authorities and exceed the capacity of the former two to restore public order and protect vulnerable populations, DoD would be required to fill the gap," he writes. "This is largely uncharted strategic territory."

Israel's massive three-day aerial assault on Gaza is likely to complicate President-elect Barack Obama's hopes of aggressively pursuing Israeli-Palestinian peace negotiations, and it risks inflicting greater damage to Washington's standing in the Arab world, according to analysts.

Indeed, if the current campaign goes on much longer and the Israelis launch a major ground invasion of Gaza as they now appear to be preparing to do, Obama could face a major international crisis – comparable to Israel's failed 2006 war against Lebanon's Hezbollah – just as he takes office in three weeks' time.

"With this assault, the fallout has already started to spread considerably beyond the constituency of people who are Palestinians," noted Helena Cobban, a veteran Middle East analyst, who cited popular protests in Egypt, Jordan, and elsewhere in the Arab world since the Israeli campaign began Saturday.

"It has already started, and we can confidently expect that the longer Israel's assault is maintained, the higher the regional stakes will rise."

The Israeli attacks, which came a week after the expiration of an increasingly shaky six-month cease-fire, have so far reportedly killed more than 300 Palestinians, while two Israelis have died in rocket attacks launched from Gaza.

While Israeli Defense Minister Ehud Barak initially insisted that Israel's war aims were designed to reinstate and strengthen the cease-fire, the former prime minister, who hopes to reclaim that post as head of the Labor Party in Feb. 10 elections, appeared to broaden them in a speech to the parliament Monday in which he pledged "war to the bitter end" against Hamas, the Islamist party that controls Gaza. Deputy Prime Minister Haim Ramon said Israel aimed to "topple Hamas."

As with the 2006 war, the administration of President George W. Bush has offered strong backing for the Israeli attack, demanding that Hamas stop firing rockets into Israel and agree to a "sustainable and durable cease-fire."

"The United States understands that Israel needs to take actions to defend itself," said White House spokesman Gordon Johndroe at Bush's ranch in Texas, where the outgoing president is spending the Christmas holiday. Johndroe called the leadership of Hamas "nothing but thugs" during a briefing on Sunday.