The most important variable in the current Persian Gulf confrontation is time. The Trump administration wants to play a long game, to draw the sanctions tourniquet ever tighter. Iran needs to play a short game, to escape the American chokehold before it becomes fatal.

This inner dynamic helps explain this past month’s events in the Gulf -- Iran’s steady escalation of deniable strikes and President Trump’s relatively restrained military response. Each side has a different playbook, dictated by their interests, resources and ability to sustain operations.

Both nations tiptoed closer to the edge Thursday, as Iran shot down an RQ-4 Global Hawk drone near the Strait of Hormuz. Trump tweeted, “Iran made a very big mistake!” but the US didn’t initially take any overt military action.

Here’s the danger ahead: Iran probably cannot break out of this squeeze play without creating a larger crisis that forces international intervention -- perhaps an Iranian attack that kills Americans and triggers a harsh US retaliation. The Trump administration does not want such a war -- at least, not yet -- because officials know that with every day of sanctions, Iran becomes weaker.

But how does this end, if not in conflict? That’s the troubling question for strategists in Washington and abroad. The US has offered negotiations (but not yet sanctions relief) through Japanese Prime Minister Shinzo Abe; Iran’s Supreme Leader Ali Khamenei spurned the offer. In accepting international mediation to end the Iraq-Iran war in 1988, Khamenei’s predecessor, Ayatollah Ruhollah Khomeini, may have drunk what he called “the cup of poison.” But Khamenei refuses, so far.

When we examine the inner logic of the confrontation, the surrounding events become more comprehensible. Each side appears to be behaving rationally, hoping to obtain its goals without the broad military conflict that neither wants. That’s mildly reassuring, but the danger of miscalculation remains huge.

Let’s start with Iran. It began to escalate its tactics in early May, after Trump did two things the previous month that tightened the noose: The US designated Khamenei’s Islamic Revolutionary Guard Corps as a terrorist organization, in effect declaring “open season” on its operatives, and the US ended any waivers on its oil-export sanctions, seeking to drive Tehran’s oil revenues toward zero.

Iran had been planning to wait Trump out. But after these strangulation moves, Tehran altered its strategy. Feeling backed into a corner, the Iranians decided, in effect, to fight their way out. Much like the Russians in Ukraine, they have mostly chosen a strategy of deniable operations through proxies. Their Houthi allies in Yemen have attacked Saudi oil pipelines, civilian airports, power plants and other targets. IRGC navy commandos appear to have stealthily mined oil tankers.

These limited tactics have not forced the US to back off, and the Iranians escalated Thursday by shooting down an American drone. A likely next step for the US would be to send aloft F-18 fighter escorts to accompany the big drones; good luck to the Iranians in that contest.

When you recognize that Trump is seeking to play a long game, some of the zigzag oddities of his policy come into focus. In the runup to Abe’s failed mediation mission to Tehran, Trump spoke ceaselessly of Iran’s supposed enthusiasm for talks; he was chumming the water. After last week’s attacks on two tankers, Trump called the incidents “very minor.” Similarly, his one-sentence tweet after the drone shoot-down was relatively restrained, and he later said it made a “big, big difference” that the plane was not piloted.

We’ll see, but for now Trump doesn’t seem to want a shooting war; he’s already waging a quite successful economic one, probably supplemented by covert actions in cyber and other domains.

Every time Secretary of State Mike Pompeo is asked publicly about an exit ramp in this crisis, he repeats that Iran should accept his 12-point list of demands, which amount to halting all nuclear development and proxy actions in Yemen, Syria, Iraq, Lebanon and Afghanistan. Basically, it’s a call for capitulation. Pompeo might settle for a smaller slice of Iranian humiliation, but why should he, when time is working in his favor?

Trump says he isn’t seeking regime change in Iran. But frankly, it’s hard to see another way that this confrontation will end -- unless Khamenei decides to take a gulp from that cup of poison.

This is a war that would be entirely unnecessary, and would have very damaging consequences for Iran, the United States and the region. But there’s an ironclad illogic at work here, and the internal dynamics of US and Iranian policy are pushing us closer to the brink.


David Ignatius
Follow David Ignatius on Twitter: @IgnatiusPost -- Ed.

(Washington Post Writers Group)