Ahmed Rashid, writing in Haaretz, outlines what he sees as a highly likely response in the Muslim world to an Israeli, or American, strike on Iran's nuclear facilities. It's a worst-case scenario, but nevertheless a plausible one (h/t Hussein Ibish). Rashid says the locus of rage would be in Shia communities, but Sunnis might also erupt, as well. By the way, if someone has a compelling counter-argument, please send it along. Rashid:
In countries that border Iran, such as Iraq, Pakistan and Afghanistan, all of which are subject to a powerful U.S. military or political presence, Iran, to protect itself against possible American incursions or sabotage, has trained local militants to attack U.S. targets in their respective countries in the event of any attack on Iran. This program had its origins during the second term of the Bush administration, when Vice President Dick Cheney spoke openly about attacking Iran. Iran organized and planned for retaliatory attacks against U.S. targets everywhere that it was in a position to arm and fund clandestine groups.
Thus, the Shia protest in the Muslim world would likely be organized and widespread, and would target Americans and Israelis, and include major acts of terrorism and extreme violence.
At the same time, anti-Americanism is reaching dangerous levels in predominantly Sunni countries such as Pakistan and Afghanistan. Both countries have extremist Sunni groups that engage in terrorism, as well as conservative Islamic parties that participate in electoral politics. Any attack on Iran could see a merging of all these Sunni elements as well as of the broader Sunni population, and one could expect widespread anger in the streets.
Such widespread and angry protests could make it almost impossible for Americans or Israelis to travel, work or do business across the Arab world and the Indian subcontinent. Such protests would almost invariably wipe out the gains and aspirations of the democratic movements within the Arab Spring countries, and lead to a reinforcing of Islamic fundamentalist parties, which could be expected to jump on the anti-American bandwagon. Widespread Sunni protests would invariably make the U.S. and NATO withdrawal from Afghanistan planned for 2014 much more difficult and possibly lead to the strengthening of the Taliban. It also could lead to a possible new intifada among the Palestinians, who in any case see little hope of an agreement with Israel on a two-state solution.