General Suleimani’s killing all but forces Iran to retaliate, most analysts say. That’s not primarily out of national pride or saving face, but because of the fundamental drive of any state: self-preservation, which includes preserving its top leadership. Killing one of those leaders is more than a slap in the face or a blow to military capabilities; it is a threat to the functioning of the state itself. Iran will feel compelled to retaliate, if only to demonstrate that killing its leaders will trigger counterattacks dire enough to deter the United States from doing so again. But it is difficult to predict how severe that retaliation will be, casting a cloud of uncertainty over the region.

Iran has an extraordinarily difficult needle to thread. It will likely aim for counterattacks damaging enough to persuade the United States that killing General Suleimani was not worth it — a high bar, given his value and the far superior American military strength — but not so damaging as to trigger an all-out conflict. If Iran succeeds, the results could be costly to the United States and its allies, but fall short of triggering outright war. But there is no way for it to know for sure what actions would meet both goals. And miscalculation could lead things to spiral out of control.