As the United States begins its campaign to destroy the Islamic State of Iraq and the Levant (Isil), many voices can be counted on to call for cooperation with Iran. Among those has been none other than Secretary of State John Kerry, who insisted that Iran’s exclusion from the Paris Conference “doesn’t mean that we are opposed to the idea of communicating to find out if they will come on board, or under what circumstances, or whether there is the possibility of a change.” On the surface, this may seem sensible, as both Washington and Tehran have an interest in defanging a militant Sunni group. But we would be wise to bear in mind two points: First, Kerry’s proviso on the possibility of change, and second, that the essential axiom of Middle East politics is that the enemy of my enemy is sometimes still my enemy. The ebbs and flows of the war on terrorism should not be allowed to conceal the fact that the theocratic Iranian regime and its attempt to upend the regional order remains the US’ most consequential long-term challenge in the Middle East.

The Islamic republic is not a normal nation-state seeking to realise its legitimate interests but an ideological entity mired in manufactured conspiracies. A persistent theme of Supreme Leader Ayatollah Ali Khamenei’s speeches is that the US is a declining power whose domestic sources of strength are fast eroding. In today’s disorderly region, Iran sees a unique opportunity to project its influence and undermine the US and its system of alliances.

Subverting allies

In Afghanistan, in the aftermath of the September 11 attacks, the misapprehension was born that the US needed Iran’s assistance to rehabilitate its war-torn charge, and this misbegotten notion has since migrated from crisis to crisis. The tactical assistance that Iran offered in Afghanistan in 2001 was largely motivated by its fear of being the next target of US retribution. Once it was disabused of that notion, Iran proceeded to lacerate US forces in both Iraq and Afghanistan by providing munitions and sanctuary to various militias. In the meantime, Tehran sought steadily to subvert America’s allies in the Arabian Gulf and to undermine the security of Israel.

Today, in the two central battlefronts of the Middle East — Syria and Iraq — Iran’s interests are inimical to those of the US. Iran’s stake in Syria has been made clear by its provision of money, oil, arms, advisers and, most important, Hezbollah shock troops to prop up the regime of Bashar Al Assad. The US’ interests, meanwhile, strongly argue against working with Iran against Isil in Syria lest it lose the very Sunni support that will be necessary to eradicate the group. By taking a firm stand in Syria against both Al Assad and Isil, US can send a strong signal to Iran’s leaders that the price for its troublemaking is going to rise.

Similarly in Iraq, any putative alliance with Iran would undo much of what the US has attempted to accomplish there — the creation of a pluralistic, unitary state that does not represent a threat to itself or its neighbours and which is not a base for terrorism. The only way that US President Barack Obama’s objective of not only “degrading” but also “destroying” Isil can be achieved is by taking back, over time, much of the territory seized by its fighters in Nineveh and Anbar provinces. This will require not only air strikes in support of the Kurdish peshmerga troops and Iraqi security forces but also significant buy-in from the Sunni tribes who formed the backbone of the uprising against Al Qaida during the surge. In addition, the sine qua non of the administration’s policy is an inclusive government in Iraq that can draw support from Saudi Arabia and the UAE. Both of these will be unattainable if there is a perception that the US is seeking a de facto alliance with Iran. [On Monday, the US said it would refuse to seek Iran’s cooperation in fighting Isil forces by being more flexible in the negotiations of six world powers with Tehran on its nuclear programme.]

During the past decade, and over two administrations, the US has been effective in estranging Iran from its European and even Asian customers. But Washington has not affected Iran’s position in the Middle East to the same degree. Beyond arms sales to Arab states and attempts to assuage Israeli concerns, the US has not undertaken a systematic effort to isolate Iran in its immediate neighbourhood. Instead of pursuing the chimera of cooperation with the likes of Khamenei, Washington should contest all of Iran’s regional assets. From the Shiite slums of Baghdad to the battlefields of Syria, Iran should be confronted with a new, inhospitable reality as it searches for partners.

The US and Iran stand at opposite ends of the spectrum of Middle East politics. The Islamic republic’s ideological compulsions and sheer opportunism make it an unlikely ally for the West. The coincidence of mutual opposition to a radical Sunni terrorist group should not blind America to the enduring threat that the Iranian leaders represent.

— Washington Post

Eric Edelman, a distinguished fellow at the Centre for Strategic and Budgetary Assessments, served as undersecretary of defence for policy from 2005 to 2009. Dennis Ross, a fellow at the Washington Institute for Near East policy, was special assistant to the president for the Middle East and South Asia from 2009 to 2011. Ray Takeyh is a senior fellow at the Council on Foreign Relations.