In an article for the January issue of International Affairs titled Iran’s ISIS policy, Dina Esfandiary and Ariane Tabatabai explain what Iran is and isn’t doing to counter the progress of the Islamic State. With Iraq bordering Iran, much of the Iranian public views the Islamic State as an immediate threat.

In June 2014, as ISIS was making substantial advances in Syria and Iraq, the Iranian state media downplayed the threat … The Iranian population, however, inferred that the group had advanced into Iranian territory. … The public apprehensions illustrate the deep insecurity of Iranians and the persistence of a vivid memory of the devastating Iran–Iraq War; they also highlight the lack of trust in their government to effectively assess and respond to such threats.

After initially downplaying the threat, write Esfandiary and Tabatabai, “As ISIS made more substantial progress, the government’s attitude began to shift. … leading it to become involved ‘from behind’.”

Then, in the light of the progress made by ISIS fighters close to Iranian borders, Tehran changed its approach to the conflict again, further increasing its involvement in Iraq in the effort to pre-empt a potential spillover across its borders. The significance of the Iraqi strategic environment for Iran is such that Tehran is unlikely to maintain its current level of engagement in Syria should the crisis in Iraq worsen or endure because of competing priorities and resources.

“An opportunity for further cooperation with the West?” the authors ask in a subhead to one of their paragraphs. Turns out,

To advance its agenda, Tehran will inevitably have to coordinate its response with the West. Western leaders have already acknowledged the need for cooperation—or, at the very least, coordination—with Iran and expressed interest in doing so. Iranian officials have prudently suggested that this would be possible.

In fact,

… despite announcements by both sides that regional issues would not be part of the nuclear negotiations taking place between the five permanent members of the United Nations Security Council … and Iran, US and Iranian officials reportedly discussed the ISIS crisis on the sidelines of the talks in Vienna in June 2014.

Out of fear of opposition from hardliners in Iran, Tehran hasn’t spoken openly about collaborating with the West against the Islamic State.

Yet, unlike the nuclear issue, the prospect of cooperation with the West in Iraq has not become a major topic of debate in Iran. Iranian hard-liners have instead focused on fixing red lines for Rouhani’s administration on acceptable outcomes for Iran’s uranium enrichment programme, in the context of fast-moving negotiations. More importantly, defeating ISIS is a priority for all across the political spectrum in Iran.

Woe to the legacy of president of the United States ― now or the next ― who is unable to make diplomatic history with Iran (and rid the Middle East of the scourge of the Islamic State in the process).