While the Trump administration’s policy of placing “maximum pressure” on the Islamic Republic, primarily through sanctions, has failed to end the mullahs’ quest for nuclear weapons, it has greatly reduced their financial capacity to terrorize the region. But more still can be done, both by the White House and by Congress, argue Mark Dubowitz, Behnam Ben Taleblu, and Richard Goldberg:

[Above all], the Trump administration should do more to strengthen its “sanctions wall of deterrence,” whose purpose is to deter market players from returning to business with Iran even if the United States rejoins the [2015 nuclear deal after the next election].

Washington needs to establish clear red lines to head off further Iranian escalation as the maximum pressure campaign continues. Last summer, Washington did not respond to Iranian regional and nuclear escalation, culminating in a cruise missile and drone strike on Saudi Arabia that knocked offline almost 6 million barrels of daily petroleum production.

While the killing of [the Iranian general Qasem] Suleimani shocked Tehran after its militias killed an American in Iraq, Washington since has absorbed repeated rocket and mortar attacks from pro-Iran militias, even after two American and one British solider were killed. The red line against the taking of American lives must be enforced. But even this high bar for the use of force can make allies skeptical about American staying power in the region while incentivizing Iran-backed Shiite militias to continue their attacks.

The administration [moreover] must safeguard gains and add to its wins. First, it should not offer Tehran any premature sanctions relief. Diminishing American leverage led to the fatally flawed 2015 agreement in the first place and has not worked in the administration’s negotiations with North Korea, in which Trump’s summit diplomacy undermined the pressure campaign. Washington should defend its sanctions wall against a new administration by designating more Iranian entities and economic sectors under multiple sanctions authorities.

Early Friday morning, Israel attacked military installations near the Iranian cities of Isfahan and nearby Natanz, the latter being one of the hubs of the country’s nuclear program. Jerusalem is not taking credit for the attack, and none of the details are too certain, but it seems that the attack involved multiple drones, likely launched from within Iran, as well as one or more missiles fired from Syrian or Iraqi airspace. Strikes on Syrian radar systems shortly beforehand probably helped make the attack possible, and there were reportedly strikes on Iraq as well.

Iran itself is downplaying the attack, but the S-300 air-defense batteries in Isfahan appear to have been destroyed or damaged. This is a sophisticated Russian-made system positioned to protect the Natanz nuclear installation. In other words, Israel has demonstrated that Iran’s best technology can’t protect the country’s skies from the IDF. As Yossi Kuperwasser puts it, the attack, combined with the response to the assault on April 13,

clarified to the Iranians that whereas we [Israelis] are not as vulnerable as they thought, they are more vulnerable than they thought. They have difficulty hitting us, but we have no difficulty hitting them.

Nobody knows exactly how the operation was carried out. . . . It is good that a question mark hovers over . . . what exactly Israel did. Let’s keep them wondering. It is good for deniability and good for keeping the enemy uncertain.

The fact that we chose targets that were in the vicinity of a major nuclear facility but were linked to the Iranian missile and air forces was a good message. It communicated that we can reach other targets as well but, as we don’t want escalation, we chose targets nearby that were involved in the attack against Israel. I think it sends the message that if we want to, we can send a stronger message. Israel is not seeking escalation at the moment.