Last week, Hezbollah chief Hassan Nasrallah threatened a regional war were Iran to be attacked by the United States amid rising tensions between the two countries. It was an expected statement of support by Hezbollah, Tehran’s closest regional proxy. But just as important, if less noticed, was what Nasrallah added immediately afterward—namely, that nobody should fear tensions escalating that far. It was simultaneously a warning to Washington and an attempt to assuage the concerns of the group’s local supporters.

Hezbollah has historically been Iran’s most effective allied militia; it has long been expected to participate in all of Iran’s wars. But domestic pressures in Lebanon have complicated such participation, and Iran is shifting its foreign policy accordingly. There are a growing number of signs that Tehran now believes the Houthi insurgents of Yemen should be their preferred regional proxy in the growing confrontation with the United States and its allies.

In mid-May, nine days after the United States sent an aircraft carrier group and Air Force bombers to the Persian Gulf, citing an imminent threat from Iran, it was neither Hezbollah nor Shiite militias in Iraq that struck back, but the Houthis, who later admitted to attacking a Saudi pipeline with drone-borne weapons. They also claimed responsibility for attacking a Saudi arms depot in Najran, a city near the border with Yemen. The incidents came well before the end of a 60-day deadline from Tehran to Europe to come up with an alternative mechanism to ensure Iran can sell its oil despite U.S. sanctions, and seemed calibrated to serve as a warning about Tehran’s seriousness: loud enough to be noticed by Tehran’s adversaries, but not large enough to demand an immediate and demonstrative response.

Iran’s shift of attention from Hezbollah to the Houthis shouldn’t come as a complete surprise. Tehran has always carefully considered which of its allied militias to activate in the specific circumstances of a given conflict. In the present confrontation with the West, Iran’s focus seems to be on signaling its seriousness, and raising the stakes of the conflict in ways that would give its adversaries pause. The goal is to ensure any military action is painful for Iran’s enemies but remains clearly short of war.

The Houthis, already at war with Saudi Arabia over the kingdom’s support of President Abdrabbuh Mansur Hadi, a man the Houthis deem a Saudi puppet, serve this function well by offering Iran the greatest degree of deniability. The Houthis have been launching attacks in Saudi Arabia for a while; the current uptick in the attacks has come in the middle of a U.N.-supported peace deal between the warring sides, but perfectly supported Iran’s interests by demonstrating Saudi Arabia’s vulnerability. The timing of the attacks strongly suggest they were conducted at Iran’s behest.

Seyed Mohammad Marandi, an Iranian-American academic and political analyst based in Tehran, said he would not be surprised if the Houthis had come to Iran’s aid. “It is possible that the Houthis did not like the pressure of sanctions on Iran,” he said. “Iran is not asking them to do anything, but I think as the Saudis and the Emiratis hurt Iran’s economy, Iran would use all its means to hurt them back.”

Michael Knights, a senior fellow at the Washington Institute for Near East Policy, said Iran’s deployment of the Houthis was a clever choice because any retaliation would fall inside Yemen and not Iran. The aim, he said, was to target the Saudis, because attacking American interests would prompt too severe a response. “It is very clear that Saudi interests would be threatened by Iran,” he said. “The question is, for how long and to what extent and until when would the U.S. tolerate it.”

Iran understands the specific risks involved in using each of its proxies. Involving Hezbollah in the present conflict with the United States would inevitably involve Israel, and almost certainly cause a wider regional war—a possibility that both Iran and Hezbollah want to avoid.

A wide range of Lebanese political analysts—including several close to Hezbollah and several critical of it—told Foreign Policy that, while Hezbollah offered ideologically committed and war-hardened fighters, Iran was wise to keep it at bay. In the slowly evolving conflict with the United States, the group was of little use to Iran. Sami Nader, a political analyst, said that Hezbollah did not have sufficient domestic backing to fight directly for Iran and jeopardize Lebanon’s fragile peace, with further debilitating impact on its economy. “Our economy is in a perilous state,” he said. “If Hezbollah aggravated the situation by intervening in the U.S.-Iran conflict, it would not be accepted by the Lebanese people.” Ghassan Jawad, an analyst known to be close to Hezbollah, said that there was an unspoken understanding between the United States, Iran, and Hezbollah that Lebanon should remain a functional state in an otherwise conflict-riven region. “Neither the U.S. nor Iran nor Hezbollah want chaos in Lebanon,” he said. “Iran and Hezbollah have planned that for now other proxies be used.”

The main reason Hezbollah is forced to take a back seat is the absence of provocation from Israel. Hezbollah has flourished as a political actor in Lebanon not just because it has always been seen as an effective resistance to Israeli aggression, but also because the group has repeatedly said that its raison d’être is defensive. To that end, Hezbollah has been treading cautiously in its dealings with Israel ever since their most recent war in 2006.

From Iran’s perspective, Hezbollah is largely redundant in the slowly simmering conflict with Washington. It already has the Houthis in Yemen and Shiite militias in Iraq at its disposal. Hezbollah would only actively come into play if there were a fully fledged war between the United States and Iran, or if the Syrian government were to decide to respond to Israel over its occupation of Golan Heights and the regular bombing of Iranian assets on its territory. Hezbollah is deeply entrenched in southern Syria with fighters and weaponry.

Kamel Wazne, a Lebanese political analyst, said Hezbollah had not yet made any decision to escalate the situation in Syria either. “There is open war in Syria,” he said. “On one side are Iran and Hezbollah and on the other the Israelis. Syria has always promised retaliation, but that day has not come yet. “It is possible that the Syrian government decides that it does not want Iran to be seen as weak and retaliates. Then, of course, Hezbollah would play a role.”

Iran’s next step depends on how much further the United States pushes. Iran is growing more desperate as its channels for selling oil are drying up in the face of U.S. sanctions. If the United States escalates its economic pressure by, for example, intercepting Iran’s tankers or imposing sanctions on companies buying its oil, Tehran is likely to expand its retaliation by proxy to include its allied Iraqi militias, which are well placed to hit American assets.

Marandi says that Iran can be expected to respond in equal measure to the threats that confront it. “JCPOA violation for JCPOA violation, war for war, and economic pain for the U.S. and its allies in return for renewed economic sanctions against Iran,” he said, referring to the Joint Comprehensive Plan of Action, the nuclear deal negotiated in 2015.

This suggests an avoidance of the major escalatory threat U.S. hawks were keen to play up when the USS Abraham Lincoln was sent to the Gulf three weeks ago. But it also signals what regime insiders, both those on the hard-line and moderate wings, have long insisted: Iran will pursue gradual steps to withdraw from the nuclear deal and to adopt a more hostile posture in the region as the standoff with the Trump administration continues.

FP