We must send a signal to Iran

From shortly after the Hamas assault against Israel, U.S. forces in Iraq and Syria have found themselves under an increasing tempo of drone, rocket, and mortar attacks launched by Iranian-backed militias. The near-daily strikes, upwards of 40 by now, while mostly repulsed by air defense systems, have injured nearly 50 U.S. personnel, if none seriously—though an American contractor was killed indirectly, suffering cardiac arrest during one of the bombardments. In response, the United States has two obligations.

First and foremost, American political and military leaders have a moral duty to protect Americans from harm. At the same time, Washington must not be baited in letting the violence in Gaza spill across the region. Therefore, it must avoid letting conflict with Iran escalate out of control. While these goals are largely coterminous, pursuing both in unison can be tricky.

The United States has pursued these goals through several retaliatory airstrikes against low-level Iranian facilities in Syria. After the first attack, U.S. Secretary of Defense Lloyd Austin insisted the strikes are a carefully calibrated warning to the Iranians to rein in their militias. “The United States does not seek conflict,” Austin insisted, “and has no intention nor desire to engage in further hostilities, but these Iranian-backed attacks against U.S. forces are unacceptable and must stop.” While signaling of intent can be strategically crucial, Austin’s overly cautious wording may have sent the wrong signals. The attacks against U.S. bases have continued.

Perhaps sensing weakness, Tehran, thoroughly undeterred, appears convinced it has a golden opportunity and is demonstrating a willing appetite for escalation and a correspondingly high tolerance for risk. It is leveraging the Israel-Hamas fight to increase its regional influence, in part by linking the increased U.S. presence in the region to its support for Israel. It’s not a hard sell. Pointing to ramped up U.S. force posture, including the arrival of an American carrier group off Israel’s coast, a nuclear submarine deployed to Middle East waters, and to the rapid up-arming of Israel with U.S. military materiel, Iran is fueling the anti-Israeli sentiment of its extremist proxies and redirecting it against the United States. Tehran’s dream is to exploit U.S. fears of escalatory spillover to push Washington to end its vestigial troop presence in Iraq—a known goal of both Tehran and its Iraqi-based militias.

Iranian confidence that it might succeed has historical plausibility, as exemplified by our pullout from Afghanistan. The pullout fit a pattern: Vietnam, Lebanon, Somalia, Iraq. Tehran has cause to doubt U.S. political resolve and staying power. Some observers fear Iran may be willing to risk doubling down. U.S. bases in Iraq are lightly manned and in remote locations. The battle-hardened militia groups could accomplish what drones and rockets never will: inflicting significant American losses or even overrunning the bases.

There are typically only three broad options to deter such attacks. First, deny the enemy the confidence that it could launch a successful assault. But, in the present context, this could only be done by increasing U.S. forces at the bases under threat, and this is politically impossible. Second, an exploitable characteristic of Tehran is typically its commitment to plausible deniability. Like a roach running from a light, Iranian mischief can sometimes be deterred by detecting and exposing it. To whatever degree we can reveal Tehran’s presence behind the militia groups attacking our bases, we should; especially if we couple it with the prospect of a direct confrontation. This corresponds with option three.

Regimes, like people, are motivated by a desire to avoid pain. An American commitment to punish Iran for the actions of its proxies may be what’s required to deter Tehran. Deterrence by punishment works by identifying what it is your enemy values and then credibly threatening to destroy it or damage it to a degree your adversary is unwilling to bear.

This might require America abandoning its sometimes over-commitment to limited, tit-for-tat retaliatory measures, born of a misunderstanding of the requirements of proportionality. Our retributive response—or, sometimes better, our threat of retribution—should instead correspond to our proper military objectives. Proportionality is not measured by what our enemy has done, but by what we intend to do. The killing of Qods Force commander Qasem Soleimani during the Trump administration might offer inspiration. The disruptive and psychological shock of Soleimani’s killing kept the Iranian regime reasonably in check for the remainder of the Trump presidency.

Certainly, the current administration must be careful to avoid unnecessarily wider conflict. But it must avoid paralysis as well. Deterrence is tricky, but doing the same weak thing over and over has accomplished nothing. Short of larger scale military operations, which nobody wants, it will be difficult to curtail the Iranian mullahs’ ability to make mischief against American interests.

But decisive actions short of all-out war just might curtail their willingness to do so.