Can a Regional War Be Avoided in the Middle East?

The U.S. strikes on the Houthi rebels in Yemen show that the war that began after Hamas launched a brutal terrorist attack on Israel on October 7, 2023, is now a regional conflict. Regional actors, including Iran and the Houthis, want to demonstrate solidarity with Hamas and gain credibility with their constituencies for being part of the anti-Israel struggle. At the same time, however, Iran wants to avoid an all-out war with Israel and the United States. But the actions of both sides might accidentally spin out of control.

Deterring a regional war will be a challenge for the United States and require restraint on Israel’s part. Thomas Schelling, the U.S. foreign policy strategist and Nobel Prize-winning economist, argued that deterrence rests, in part, on the threat of inflicting more pain—what he called “latent violence.” This approach entails the United States using calibrated force against Iranian-backed groups in Yemen, Iraq, and Syria, signaling that it is prepared to use more force if necessary, and then following up if it is required.

The threat of latent violence is particularly important to send to Iran. Over the past decade, Iran and its paramilitary arm, the Islamic Revolutionary Guard Corps (IRGC)-Quds Force, have strengthened their relationships with partner forces in Lebanon, Syria, Iraq, Yemen, Gaza, the West Bank, and other areas in the region. Since October 7, the head of the Quds Force, Esmail Qaani, has promised to support Hamas in an “axis of resistance” and visited Iranian-backed groups in Syria and Iraq.

Israel’s deadliest foe is Lebanese Hezbollah. The risk of an all-out war with Hezbollah has loomed since October 7. Since that date, Hezbollah and various Palestinian groups it controls have attacked Israel more than 200 times, while Israel has struck over 1,200 targets in Lebanon. Twelve Israelis have died, and Hezbollah reports it has lost around 150 fighters from the attacks and Israeli strikes have killed 20 Lebanese civilians. Israel has also struck Hezbollah commanders and senior Hamas figures in Lebanon. A member of the country’s war cabinet warned that if there is no diplomatic solution soon, Israel’s military will act decisively.

Israel and Hezbollah clashed in 2006 in a 34-day war that left both sides reeling, with at least 157 Israeli dead, perhaps 500–700 Hezbollah fighters killed, and as many as 2,000 Lebanese civilians dead. The hostilities ended with UN Security Council Resolution 1701, which called for the Lebanese state, not Hezbollah, to assert control of the border area.

Since the war, however, Hezbollah has deployed its forces to the border, at times disguising its operatives as members of a fake NGO, Green Without Borders, to infiltrate the area. Hezbollah forces include several thousand elite “Radwan” fighters that have trained for cross-border attacks on Israel. Hezbollah has also built a massive rocket arsenal, estimated at 150,000, which includes some precision-guided systems. Although Iron Dome and other Israeli missile defense systems have proven effective against limited numbers of rockets, Hezbollah could overwhelm these systems with massive salvos.

Despite Hamas’s wishes, the October 7 attack did not signal the beginning of an all-out regional war against Israel. Hezbollah, unlike Hamas, cares about its constituents and fears a repeat of 2006. With its attacks, Hezbollah seeks to show solidarity with Hamas, not launch a broader conflict, and has carefully selected targets (and used Palestinian proxies for any cross-border infiltration). Israeli officials told us that they recognize Hezbollah has, for now, selected its targets with care to avoid escalation to all-out war.

Fearing a Hezbollah attack, Israel evacuated dozens of towns near the border, including over 80,000 Israelis. For now, Israel has bolstered its military forces in the north, but many of these are reservists, and Israel cannot mobilize them for long without tremendous harm to its economy. It must also eventually convince residents to return to their homes.

The potential for an expanding war includes Israel’s other northern neighbor, Syria. Iran and Hezbollah came to the regime’s rescue when it neared collapse after it descended into civil war in 2011, and now both have a greater presence on the Israel border. Israel at times launches strikes on Iranian Quds Force officers and other Iranian assets in Syria.

Iranian-backed groups have also used drones to attack U.S. forces based at al-Tanf, along the Jordanian border, and at the Conoco gas field in eastern Syria. These attacks have injured dozens of Americans, leading the United States to target Quds Force infrastructure in Syria. U.S. officials claim there is “very clear messaging through multiple channels. And the message is, to Iranian senior leaders, ‘We want you to direct your proxies and militia groups to stop attacking us.’” Yet the attacks continue.

One of the post-October 7 surprises is the emergence of a new player in the Israel-Palestinian dispute: the Houthis in Yemen. The Houthis, a rebel group, are the de facto government of much of Yemen. The Houthis have fought in a civil war for almost a decade, with almost 400,000 people dying and regional powers like Saudi Arabia and the United Arab Emirates trying, unsuccessfully, to counter them. Their unsubtle motto is “God is the Greatest, Death to America, Death to Israel, A Curse Upon the Jews, Victory to Islam.” They have limited support in Yemen and rule brutally there, but now they are basking in the admiration of many Yemenis and much of the Arab world for their anti-Israel actions. Iran backs the Houthis, providing them with weapons and training, but it does not control them.

Since October 7, the Houthis have attacked shipping in the Bab el-Mandab Strait as well as launched missiles at Israel, most of which U.S. forces intercepted. The attacks, however, have convinced major shipping companies to avoid the area, a blow to the economies of Egypt and Jordan as well as Israel, and increasing the overall costs of shipping throughout the world.

The United States has formed an international task force with Bahrain, Canada, France, Norway, Spain, and the United Kingdom, in addition to using U.S. Navy vessels to counter Houthi attacks. The recent U.S. attacks on Houthi targets, which struck drone and missile sites, radars, and weapons storage areas, were designed to send a message to the Houthis rather than initiate a larger struggle. But the Houthis still retain significant offense capabilities and will likely continue to fire missiles and drones at ships transiting the Red Sea.

While the attacks in Yemen, Lebanon, Iraq, and Syria since October 7 are concerning, they have largely been contained to low-level artillery, rocket, air, and drone strikes, with only limited infrastructure damage and casualties. But escalation to full-scale war is possible and would throw the region into turmoil.

The challenge for the United States will be to deter Iran and its partner forces from escalating the conflict into a regional war by adopting a calibrated use of force today and indicating that it has the capability and will to use additional force if necessary in the future. Of particular importance is signaling that the United States is prepared to strike—and continue to strike—targets of value to Iran and its partners in the region, such as military bases, weapons depots, arms production facilities, command and control centers, and training locations.

In Yemen, the United States should adopt a firmer response to the Houthis, including increased attacks against Houthi infrastructure, as long as Houthi attacks persist. The United States should also adopt a tougher approach to Iranian-backed groups in Syria and Iraq if attacks continue against the United States, Israel, and other international targets. In Lebanon, the United States should push for much more effective implementation of UN Security Council Resolution 1701, especially near the Israel border.

The United States also needs to convince Israel to avoid escalating the war, particularly against Hezbollah. Another war in Lebanon would lead other Iranian proxies to increase attacks on U.S. forces, making it hard for the United States to avoid being sucked into a far more massive conflict. So far, the Biden administration has successfully convinced Israel not to escalate, and stronger U.S. actions against various Iranian proxies like the Houthis will help convince Israelis that the United States stands behind them.

Washington should also convince Israel to allow more humanitarian aid into Gaza and reduce the intensity of operations to lower the death toll among Palestinian civilians. Both of these will reduce (though hardly end) the anti-Israel outrage that feeds militant groups in the Middle East.

Adopting this approach will require deft diplomacy and the continuing deployment of some U.S. military assets in the Middle East, including at least one carrier strike group. A U.S. carrier strike group has significant capabilities that can be used across the Middle East, such as missiles for long-range strike, air defense, fighter aircraft, and intelligence collection.

Deterrence rests, in part, on the credible threat of more pain. These actions will not guarantee that a regional war will be averted. But they should impact the cost-benefit calculations of Iran and its partners and make it clear that a regional war will be devastating—and that is a big step forward in effective deterrence.

Daniel Byman is a senior fellow with the International Security Program at the Center for Strategic and International Studies (CSIS) and a professor at Georgetown University. Seth G. Jones is senior vice president and director of the International Security Program at CSIS.

Daniel Byman
Senior Fellow, Warfare, Irregular Threats, and Terrorism Program
Seth G. Jones
Senior Vice President; Harold Brown Chair; and Director, International Security Program