Keeping U.S. Power Behind Israel Will Keep Iran at Bay

Until Iran’s barrage of missiles and drones against Israel, the two countries had avoided open military intrusions into each other’s territory. Tehran most often acted through proxies, and Jerusalem via bombing runs and unacknowledged assassinations in the region.

Iran’s unprecedented attack this weekend, which failed to kill a single Israeli, has perhaps now opened the clerical regime to a major reprisal. The White House clearly does not want Jerusalem to undertake such a response, fearing escalation that could bring the United States into a regional war.

But the chances are good that Israel will strike back to deter future direct attacks. And the best way for Washington to limit the expansion of this conflict is to signal clearly its intention to support an Israeli counterattack. It’s the recurring military paradox: To contain a war, a belligerent sometimes needs to threaten its expansion. Iran’s internal situation, its memory about past U.S. military action and a conspiratorial worldview all support this strategy.

An Iranian regime well aware of its weaknesses knows how convulsive a war with Israel and America would be and how unwelcome it would be received by a restive populace already protesting a dysfunctional economy and increasing oppression. Many within the elite are surely angry at having fallen from the inner circles of power and wealth as the 84-year-old supreme leader, Ali Khamenei, engineers his succession.

A powerful Israeli response could include a preventive strike against Iran’s nuclear sites. In what may prove a miscalculation, Mr. Khamenei is not known to have given the green light to assemble a nuclear weapon. Why strike Iran hard and leave its atomic ambitions undamaged? Washington will surely want to lessen the consequences in the region from such an attack. To do that, the White House will need to make Tehran understand that U.S. forces will immediately intercede if Iran then tries to escalate.

To be sure, Israel and America may both be at fault for giving Mr. Khamenei the impression that they had no appetite for escalation. Tehran has abetted Islamic militants who have killed a lot of Israelis and Americans while seeming to be immune from a direct attack. The occasional Israeli and American assassination of Iranian military men on foreign soil, or in Iran without fanfare, actually highlighted a reluctance to confront Iran more directly.