The latest round of nuclear talks between Iran and the P5+1 (U.S., UK, France, Russia, China and Germany) began last week in Geneva. The issues involved are well-known to Patriot readers so we will not recite them here. But an interesting new wrinkle has emerged, and it bears close scrutiny in the coming weeks and months.

Various Iranian officials, all speaking on condition of anonymity, have made clear Iran wants a quid pro quo in the nuclear talks for any cooperation Iran provides in dealing with the growing threat of the Islamic State in Iraq and the Levant (ISIL). Iran is in a unique position to provide meaningful assistance in the fight against ISIL – all the more so after Barack Obama ran for the exit in Iraq in 2011. With no U.S. military presence to speak of in Iraq, Iran is well-positioned to provide intelligence, logistics, training and even kinetic assistance to Iraqi forces that the United States cannot provide. Iranian Qods Force units have been supporting Iraqi forces for several months now in an attempt to keep Islamic State forces out of Baghdad, and there are credible reports that Iranian SU-25 ground attack aircraft provided to Iraq are being flown by Iranian pilots.

Both U.S. and Iranian officials have downplayed and even outright denied any possibility of military cooperation between the two nations. But as the fight escalates – as it must if it is to have any meaningful outcome – Iran’s leverage will only grow. Iran has significant ground forces, including large and reasonably competent special forces, that could go to Iraq to assist their Shia cousins. Iranian aircraft can easily reach areas where the Islamic State operates, and the Iranian government is far less concerned about having pilots shot down and captured than is the United States.

In a different setting, the U.S. would welcome such assistance from a nation located near ISIL’s operating areas, but there is no upside to partnering with Iran. First, it would give prestige and respectability to the world’s leading pariah nation to be seen operating with the U.S., especially as so few other nations seem willing or able to do so (we’re looking at you, Europe). Furthermore, Iran might plausibly be able to achieve military ends the U.S. cannot, thereby increasing its stature.

Second, cooperation would expand Iran’s existing influence over the Iraqi government, which is already a major hindrance to stability in Baghdad. In fact, it would continue Iran’s 35-year effort to portray itself as the indispensable nation of the entire Middle East.

Third, Iran would gain precisely the leverage it seeks in the nuclear talks if its military forces were carrying a sizeable part of the load in fighting the Islamic State.

For all of these reasons, the Obama administration and especially Secretary of State John Kerry must – must – resist any efforts by Iran to link the nuclear negotiations to Iranian help against ISIL. Iran will act as it deems necessary against the Islamic State in any case, but it should not expect or receive any payoff in nuclear negotiations.