The deterioration of Iraq into sectarian violence demands the same strategy espoused by Treebeard the Ent in Tolkien’s The Two Towers: “Don’t be hasty.”

The al-Qaeda offshoot ISIS added the strategic Iraqi city of Tal Afar to its prizes Monday, and took another step towards its stated goal of establishing a Sunni Islamic state across Syria and Iraq. Secretary of State John Kerry has said Washington is “open to discussions” for cooperation with arch-enemy Iran to return power to Iraq’s Shiite prime minister Nouri al-Maliki, according to the AP.

The loss of Iraqi cities that Americans died to gain is painful, but that pain must not send us staggering into our next disaster. If we learned nothing else from the first encounter in Iraq, let us at least remember to make a plan before we go in—preferably a plan that considers the millennium-old forces of sectarianism that define so much of Middle Eastern politics.

First of all, the Iranians are not—or at least, should not be—our only allies in a quest to prevent Iraq from becoming the threatening extremist Sunni state that ISIS desires. Nor is it incumbent upon America to doff the hat of the honest broker and side with the Shiites amid sectarian war. The United States seeks to curb all violent extremism in the Middle East because it is a breeding ground for terrorism. American leaders hope to neutralize the Sunnis of ISIS with the Shias of Iran, but the lessons of both Syria and the Lebanese civil war of the eighties demand something more nuanced.

If we want to save Iraq, we must keep our friends close before we pull our enemies closer. First, we must reach out to the Kurds of northern Iraq, who have so far been the only winners in this mess. The Kurdish Peshmerga took the city of Kirkuk with ease. They probably won’t want to return it, but they might be convinced to fight ISIS for Iraq now in exchange for a promise of greater sovereignty later.

Extending a friendly hand to moderate Sunnis will be more difficult. Iraqi Sunnis feel so disenfranchised by Maliki’s repressive policies that many have welcomed the ISIS takeover. Convincing them that a Sunni extremist regime is not in their best interest may require hard bargaining. Maliki’s power is weak; a fresh alternative from within the government might be needed, but the United States could help by insisting he do some actual power-sharing with Sunnis. 

Then, and only then, can a partnership with Iran be approached, but on our terms. After all, ISIS is not an existential threat to the United States, but to Iran. If ISIS prevails, the United States will have lost a key battle, but Iran will have lost one of its only friendly neighbors to a trigger-happy arch-enemy that rules its holiest cities. The Iranians should bring some concessions of their own to the bargaining table, perhaps in the form of reduced impact in Syria, or maybe a nuclear deal to our liking.

There is no shame in fighting fire with fire in Iraq, but Iran still has more to lose here than we do. Though we fight in the Middle East rather than Middle Earth, we musn’t be hasty in going to war.