I love the hubris of Americans, who have unilaterally invaded two Muslim countries since 2001, and reduced them to smouldering hellholes without a shred of believeable evidence, to go threatening Muslims with a nuclear attack on their holy sites. Add this to the fact that the Americans have been the only people to have utilised nukes on people, namely Hiroshima and Nagasaki!
But let me add to the theory that the Americans blunder around and create the animosity Mad Mac claims is unwarranted. I've outlined the duplitious history of American involvement in Middle Eastern politics and the Muslim world in another thread. Senator Tancredo, Poetess and Mad Mac's response have given me gold here. You see, as of this moment, you Americans fight an assortion of nutjob Jihadists; some who are on various Intelligence Organisations payroll (like Abu Nidal for Mossad, Bin Laden - CIA, before he died), some who've been duped by the selective interpretation of verses and hadith, and some who just love killing and mayhem, and love the idea of going to heaven and getting 72 (non-existent) Virgins.
But let us entertain a hypothetical attack on Mecca and Medina, in response to an dirty bomb attack on an American City. In the minds of the Muslims in Iraq, Palestine, Afghanistan, Lebanon who've so far, suffered more in the aftermath 9/11 than any other group, is it the 'War on Terror' or 'War on Islam'? What will the residents of Saudi Arabia, Egypt, UAE, Kuwait, Bahrain and Oman, all who've lost their most their most important City, do? Will the Chinese Muslims, Thai Muslims, Indian Muslims, the mases of Pakistan, Malaysia, Indonesia do when this irrevocable act is carried out?
Simple. You'll have confirmed the deepest fears of every Muslim. What need would they have for moderation or any other such nonsense being spewed by Americans while they simultaneously encouraging as much extremism possible with its policies? What recourse is there, but the purifying fundamentalist nutjob Jihadist theology of those who you were fighting to eliminate? You'd make all those theologians who'd dedicated themselves to preaching against extremism into idiots, dupes, collaborators, and a ripe target. You'd effectively eliminate any moderating influence, and turn the majority of Muslims into unstable extremists, who are then easier to manipulate, as the Islamists in Algeria will attest to.
You'll create more terrorists, and havoc as you have done in Iraq, but across the Muslim World. And all while trying to fight said terrorists. Who would benefit most from a hypothetical chain of events such as this? Not the Americans, because they have to go put out the fire they unwittingly (or wittingly) created. Thousands of American lives will be lost, and the nukes will be brought out again in a bid 'to end the war and save servicemen's lives' schtick! Its certainly not Muslims, including those duped into the Jihadist mentality, because they will die in droves! Its certainly a boon for the Islamists who have a different master, and those Islamists who just like the killing. Israel will finally have an excuse to get rid of the the troublesome Palestinians they've brutalised for 60 years. It'll also have an excuse to get rid of the Lebanese, Syrians and Jordanians, and incorporate their lands into the Eretz Yisrael concept they've been gunning for since Independence.
Judging from the USS Liberty incident, where the Israeli's were quite prepared to kill 34 American servicemen, any dirty bomb would be more likely to come from Mossad than any terrorist lurking in an Afghani cave, Iraqi cellar or any of these bogus and discredited sleeper cells, paraded in the media as legitimatw and quitely dropped when its found to be trollop.
Remember the Miami cell, who believed in training their minds and bodies using the Bible.

Oops, this Al Qaeda terrorist cell isn't even Muslim!