Iranian foreign policy is still a major question mark, even as Western delegations stream through Tehran in the wake of a nuclear deal that promises an end to sanctions and international isolation. But there is no denying that Iran is a major regional power, which holds the real potential of becoming a working partner with the West on a number of fronts.

Most urgent, among the ways Tehran could move back into the geopolitical fold is in helping to crush the Islamic State (ISIS), and similar jihadist groups active in Syria, Iraq and beyond.

So how can Iran help?

1. REGIONAL (AND RELIABLE?) COUNTERWEIGHT

As a violent faction of the Sunni branch of Islam, ISIS abhors Iran, where Shia Muslims dominate. Iran and Iranians are thus a prime target for ISIS, and would be therefore a natural ally (if only of convenience) of its many other enemies. As a starting point, Iran has raised its voice to warn ISIS not to approach its borders. While none of the regional powers — even Sunni-dominated regimes — is safe from a group keen to carve itself a "caliphate" in the ruins of the Middle East, the West and Russia suspect that some are less than entirely determined to fight ISIS. In the political miasma that is the Middle East, the West thus sees Iran as fully and strategically committed to combat. It is of course a delicate diplomatic balance, as Sunni regimes look at any collaboration with Iran with great suspicion, and some may even see ISIS and other Sunni radical groups as a check on Tehran's ambitions.

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The Jamkaran Mosque in the Iranian holy city of Qom — Photo: Fabien Khan

2. FRONTLINEFORCE

Iran has the military capabilities, manpower and geographic proximity to fight ISIS, and has already been engaged in operations that have pushed back the jihadists' advances in Iraq in particular. Indeed, its stated hostility to ISIS and groups like al-Qaeda or the al-Nusra Front may be more convincing than certain other regional states. The snag perhaps is that, like Russia, Iran is not just fighting terrorism but also bolstering its allies, notably Syrian President Bashar al-Assad, whom the West wants ousted. As Ali Akbar Velayati, a foreign affairs adviser to Iran's Supreme Leader Ayatollah Ali Khamenei told Iranian daily Sharg this week, Assad is Iran's "red line." So while it may help crush ISIS, its intention to keep meddling in Syria — not to mention Lebanon — may continue to fuel regional intrigue. Velayati made sure to add that Iran is now "the most powerful country participating in events in Syria."

3. LEAN ON ASSAD

For better or worse, Iran has the power to sway the Syrian regime. President Assad keeps looking less like a leader and more like a client of Russia and Iran, though one should never overlook his own ruthlessness and ferocity. The West might be interested to know whether or not Iran could force Assad from power: Could Assad survive without Iranian cash and arms and the Hezbollah militia, paid for by Iran? He might choose to rely entirely on Russia, another traditional ally of the Assads — both father and son. But Iran could ultimately apply the kind of pressure that would make the difference in paving the way for regime change in Damascus.

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Syrian President Assad during his visit to Moscow in October — Photo: Kremlin

4. VIRTUOUS CIRCLE

Here's the dream scenario for those rare optimists that still exist: Eased back into the international fold, Iran could begin to see the many advantages of moderation. Once the Iranians bet on a policy of deradicalization, and move closer to the West, the Saudis might start talking to them. The two regional rivals maintain minimal diplomatic courtesies, but seemingly diverge on almost every issue that arises. Beyond the division between Shia and Sunni Islam — and who knows how important this really is in politics? — since the 1979 revolution in Iran, the two states have come to symbolize opposing ideologies. One is "revolutionary" and friendly with disruptive states; the other, a friend of capitalism and the West. Under the Shah, in the 1970s, the Persian Gulf monarchies entertained ties with Iran that were actually quite cordial. Their interests and inclinations were not far apart. But for at least a decade after 1979, Iran was suspected of backing all manner of subversive enterprises and dastardly deeds, broadly intended to ensure that its revolution — or any revolution — would happen in neighboring states and beyond. Iranian progression toward ideological moderation could open diplomatic doors, and that could be like pulling the rug from the radicals.

5. INTELLIGENCE SOURCE

Rapprochement with the West could produce intelligence sharing with Western powers, though that seems a taller order. In recent days Iran's "cyber police" declared it had detained over 50 people promoting ISIS and its ideas on the Internet, and its head said Iran duly collaborates in this domain with Interpol, the global network of police cooperation. Like reports of big drug hauls, it sounds like good news, even if the larger context remains opaque. For the West, Iran's role in fighting fanaticism is still mostly a hypothetical scenario, and a complicated one at that.