Supporting Assad remains the only realistic path that will return us to the relative stability of the pre–Arab Spring days, and that will defeat ISIS. No one is more motivated to defeat ISIS than Assad, who would like to reassume Syria’s internationally recognized borders and seek revenge on atrocities that ISIS has committed against captured Syrian soldiers. In return for supporting Assad, the U.S.-led coalition could lobby for amnesty for other fighters — such as Kurds, Turkmen, and non-ISIS-aligned Sunni groups — who are willing to put down their arms.

Assad is a viable source of stability also because of his unconditional support from Iran, which fears and detests ISIS for the threat it poses to Shiite dominance of the region. To reiterate, strengthening Iran’s strategic position is no one’s leading choice, and Tehran’s sponsorship of Hezbollah destabilizes Lebanon and threatens Israel. But since the 2006 war with Israel, Hezbollah has mostly kept its ambitions in check and has made efforts to gain political legitimacy. More broadly, since the fall of Saddam, the specter of a Shiite hegemony that spreads across the Levant has paled in comparison with the horrors wracked by Sunni extremist terrorism. We face two undesirable choices, and one is clearly better than the other.

Despite the benefits of supporting Assad, the idea is a non-starter within Washington’s foreign-policy establishment and among nearly all the presidential candidates. I recently posed the question to a Middle East expert at the center-left Atlantic Council, and to a prominent writer at Commentary magazine. Both reacted incredulously, dismissing it out of hand. “Impossible. Assad has to go — he just has to,” remains the bipartisan refrain. When I pressed, both started down the well-worn path, arguing that we must find the “moderate Syrian opposition.” The think-tank expert at the Atlantic Council went on to claim that the moderate opposition would not actually need to conquer and govern the country, only to rebel enough to entice a coalition of “stakeholders,” including the U.S., Russia, and Iran, to come to the table for a grand agreement that would have Assad step down, with a transition to a consensus successor. This is unrealistic, wide-eyed idealism. Meanwhile, the Commentary writer asserted that Assad had lost all moral authority and that the other ethnic groups would never accept him again as their president. This line of thinking offers no constructive alternative to calming the current chaos, and it ignores the fact that Syria was never a democracy of the governed, and that the Assad family never held moral authority in their four decades in power