Six months in, the U.S. and Israeli war on Iran has settled into a stalemate. Neither Washington nor Tehran can achieve a clear military or diplomatic victory. Instead, the two sides have found themselves locked in a mutual blockade of oil and other shipments through the Strait of Hormuz and into Iranian ports, with no obvious way to change the status quo. The costs of accommodating the other side’s demands to end the stalemate are so high, and the costs of the stalemate sufficiently low, that a mutual blockade has emerged as the least bad option for both the United States and Iran for the foreseeable future.

This situation may not be ideal for Washington, but it avoids both defeat and escalation. It also works to the United States’ advantage over time: as the blockade drags on, Tehran’s position is likely to weaken faster than Washington’s. The United States has its own ample oil supplies to draw from, whereas nearly the entirety of Iran’s oil exports—and therefore much of its hard currency—has been cut off. An ongoing blockade that gradually ratchets up pressure on Iran could make Tehran more flexible in negotiations with the United States, leading to a compromise that Washington could accept. The challenge is to ensure that Tehran does not choose to respond to its worsening position by escalating its attacks and starting another regionwide conflict that ensnares the United States.

U.S. policy should focus on avoiding the most disruptive contingencies, especially Iranian escalation, and settle for maintaining dual blockades indefinitely. If Iran is unwilling to concede, Washington can slowly erode the Iranian economy and military while ensuring that Tehran cannot rebuild the strong regional position it enjoyed before the Hamas attack on Israel on October 7, 2023. At this stage, maintaining the current U.S. position is the most effective way of fighting—and winning—this war.

In June, Washington and Tehran agreed to a memorandum of understanding to first establish a cease-fire and open the Strait of Hormuz and then to sign a permanent deal within 60 days to resolve long-term issues in the bilateral relationship, including restricting Iran’s nuclear program and removing U.S. and international sanctions and other financial penalties on Iran. But it fell apart before a final deal could be reached largely because Iran failed to fully open the strait. With diplomatic solutions going nowhere, both Washington and Tehran are now hoping that the economic pressure each can put on the other—and in the case of Iran, on the global economy—will force its counterpart back to the negotiating table on terms that will resolve the blockade in its favor.

A blockade comes with costs for Washington. Keeping the strait closed is raising gas prices and increasing inflation in the United States, an especially sensitive issue as the November midterm elections approach. Prices could rise further if Iran finds a way to limit the millions of barrels of oil that bypass its blockade and are transported through the Strait of Hormuz daily. And the United States has already used up many critical munitions and strained its troops in the region by keeping the war going.

But the operation has been relatively affordable compared with past........

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