There is a hard and fast rule in the Middle East: always expect the unexpected. The, so far, successful “Blitzkrieg” of the radical Sunni Islamic State in Iraq and Syria (ISIS) is a case in point – but so were others before: the creation of al-Qaida and its ability to attack the US on its home ground, was one, the “Arab Spring” and its chaotic consequences for the whole region (though, to its credit, Israeli intelligence took a less panglossian view than most in the West) was another. And now it is ISIS and what looks like the rapid unraveling of Iraq, albeit the implications of the mayhem there and in Syria are unfortunately much wider.As Professor Louis René Beres of Purdue University put it in a recent article, the ongoing turmoil in Iraq and Syria “signals potentially catastrophic regional transformations” which could lead to chaos all over the Middle East – with plausibly dramatic consequences for the security of all states in the region, or even beyond. ISIS, though similar in its Islamist ideology and outlook to other jihadist organizations around the Muslim world, is different in one important respect: its aim is not merely to supplant the regimes in various countries, but to erase national borders altogether and create a radical Sunni caliphate in their place, first in Syria and Iraq, then in the rest of the Middle East – and later in North Africa and parts of Europe.ISIS’s next target could be Jordan which, in spite of its generally effective military capabilities, may be deemed especially vulnerable due to its own home-grown Islamist elements and because among the hundreds of thousands of refugees which have entered the country since the beginning of the Syrian rebellion, there may be more than a few who are sympathetic to ISIS’s cause. The threat to Jordan, among other things, once again underscores the importance of Israel as America’s only firm strategic ally in the region – and the significance to both, as well as to others in the region, of their defense-related ties.In this connection, it is clear that Israel, of course, cannot afford to turn a blind eye to the turmoil in Iraq and elsewhere – not only because of ISIS’s ideological expansionist designs on itself, but more concretely, because Israel’s own optimal “strategic depth” is the eastern border of its Jordanian neighbor. It is in this context that one must also regard Prime Minister Binyamin Netanyahu’s announced plan for constructing a security fence all along the Jordan Valley. Though this may not be popular, it should be pointed out that this, whatever the outcome, is bound to have also financial implications, i.e. Israel’s defense budget will probably have to be increased again, above and beyond the recent NIS 1 billion increase – meaning that either taxes will have to be raised or other budgetary allocations cut.Obviously, this new configuration of jihadism will also impact America’s efforts to combat Islamist terrorism; while up until now those efforts mainly focused on eradicating disparate terrorist groups in the not-always-coherent al-Qaida network, the US will now have to reckon also with the territorial aspects of jihadism, which may necessitate measures quite different from those employed until now, potentially including the kind of outright military steps which the Obama administration had been eager to avoid.Be that as it may, the crisis in Iraq, and indeed the ongoing violence in Syria, are not the sort of civil wars the Middle East has known for ages, nor just a religious bloodbath between Shi’ites and Sunnis – but a “to the death” struggle between two competing forces for overall geopolitical superiority and hegemony in the Middle East as a whole - a struggle in which Shi’ite Iran is playing an increasingly important role.One probable reason for the growth of ISIS was the West’s failure to sufficiently support, with arms and money, the non-Islamist rebels against the Assadists in Syria, as a result of which the Islamist rebels gained the upper hand. Turkey also must bear part of the blame. By allowing ISIS to proliferate across its border with Syria and allowing it easy access to all the battlefields there, Ankara now pays a steep price, including in economic terms, for the chaos it helped to create. Soli Ozel, a Turkish political analyst, has described the rapid fall of Mosul in Iraq to the ISIS insurgents as “the epitome of the failure of Turkish foreign policy over the last four years,” a failure which, not to forget, also included its strained relations with its natural allies, the US and Israel.Though late, but hopefully not too late to cope with the rapidly expanding crisis, which the US now realizes, also affects vital American interests, including, but not only, oil - Washington is weighing different options regarding how to deal with it in both political and military terms.Astoundingly, there are those who favor cooperating with Iran in order to bolster the disintegrating military forces of Baghdad’s Shi’ite rulers – or in the words of US Secretary of State Kerry: “the Obama administration is willing to talk with Iran.... And is not ruling out potential US-Iranian military cooperation in stemming the advances of Sunni extremists,” explaining that the US was “open to discussions if there is something constructive that can be contributed by Iran.”There were also rumors that in his recent meeting in Geneva with the Iranian delegation to the nuclear talks, US Deputy Secretary of State Bill Burns raised the possibility of cooperation with Iran on the Iraqi situation. For appearance’s sake the Iranians seem to be playing hard to get, though they better than anyone else realize that any role ascribed to them in Iraq by the Americans would be a significant boost to their geopolitical ambitions – not only with regard to propping up their client government in Baghdad, but more importantly also to their strategic designs in the region as a whole. In connection with this, Republican Senator John McCain has commented: “The reality is, US and Iranian interests and goals do not align in Iraq, and greater Iranian intervention would only make the situation worse – the United States should be seeking to minimize greater Iranian involvement in Iraq right now, not encouraging it.” Indeed, the idea of cooperating with Iran (!) must be deemed both illogical and immoral.It is clear that any warming of the US-Iranian relationship – and this would be the inevitable result of an America-Iranian synergy in Iraq – will grant the Ayatollah regime greater scope for its nefarious activities in the region, as well as against its own people, just as it would automatically strengthen its hand in the nuclear talks with the “five plus one” (US, Russia, China, Britain, France plus Germany) – and open the door to a permanent Iranian military presence in Iraq. This in turn would, among other things, result in a growing threat to the security and integrity of both Jordan and Israel- while Iran’s proxy in Lebanon and Syria, Hezbollah, which aroused a great deal of antagonism among Arab peoples around the region because of its involvement in the Syrian tragedy on behalf of President Bashar Assad – would get a new lease on life from Iran’s enhanced position. Furthermore, Washington’s traditional Sunni allies in the region, though alarmed by ISIS, would not look very favorably on the US aligning itself with a Shi’ite Iran whose ambitions threaten their basic interests, perhaps their very existence.The threat posed by ISIS must, indeed, be stopped – and the US has the means to do this – but none of this justifies a counterproductive and immoral decision to join forces with Iran.This isn’t a case of “good guys” and “bad guys” – both being equally bad in this case – but with one of them, Iran, racing towards attaining nuclear arms, threatening genocide against another country, making an all-out effort to undermine the interests of the US and its allies in the region – and directing and funding its own brand of terrorism around the world. If ever there was a case of “a plague on both their houses,” this is it.There are no easy answers. One would, however, like to trust American policy makers to be sufficiently prescient to make the right decisions.Though the situation in Iraq indeed seems increasingly chaotic, complete disaster may still be avoided by decisive American action – in fact, this would be precisely the sort of situation President Barack Obama referred to in his recent West Point speech, justifying unilateral actions where American vital interests were involved.The author is a former Ambassador to the United States.