We should be asking two questions: Why now, and What now? The most obvious answer to the first is that Iran escalated its war with the United States by attacking the embassy in Baghdad, and that Soleimani’s assassination was the response Iran could (or should) have predicted. Unlike other Iranian escalations, this one came close to being irreversible—embassies, once overrun, cannot simply reopen after the protesters have finished looting the office supplies—and required a quick deterrent reply, enough to force Iran to pause and recalculate. Soleimani posed an ongoing and lethal threat. The other, more worrying answer to Why now? is that the president is impulsive, and wages war without much thought.
What now? Strangely, this question is in some ways easier to answer. We are, as Andrew Exum writes, at war, and you do not have to be Kreskin to know that Iran will retaliate. The Soleimani lesson—what he crystallized into doctrine for Iran—is that for a weak power like Iran, geostrategy works only by indirect confrontation. You find unexpected pain points in your enemies, nerves left exposed here and there in forgotten places. Many are predicting attacks on American interests abroad: embassies, civilian targets, oil infrastructure in Saudi Arabia. But the list of predictable targets ends where the Iranians’ list of attractive targets starts. We have traded acute chaos in Baghdad for an extension and escalation of our permanent war against Iran in the region.