With the assassinations of two prominent militant leaders in Beirut and Tehran, the Middle East crisis has reached another inflection point. Whether these events presage a turn toward more active warfare or will pass as spikes in what has otherwise been a steady stream of transnational violence, is unclear. But what should be unmistakable is that the Middle East is already in the midst of a regional war. And that war is intensifying.

The most recent round of escalation was sparked by a rocket attack on the town of Majdal Shams, in the Israel-occupied Golan Heights, which killed 12 children from the local Druze community on Saturday. Israeli and US officials blamed the Lebanese group Hizbollah, whose months-long rocket campaign on its southern neighbour has forced the depopulation of northern Israeli towns and villages. Hizbollah’s leadership denied involvement but offered no credible alternative explanation for what occurred. That the victims were ethnic Arabs, and not Jewish Israelis, pushed Hizbollah into damage control, but denials and spin could not undo the grim reality of the strike. Israel was compelled to respond.

A hurried diplomatic effort led by American officials sought to encourage Israel to calibrate its response to avoid potential escalation. Washington was right to be concerned. An all-out war between Israel and Hizbollah would be devastating for Lebanon, further endanger Israeli civilians, and could invite intervention by Iran and its regional proxies. A war in Lebanon would likely also impede efforts to reach a ceasefire in Gaza and delay the release of the remaining Israeli hostages.

That effort doesn’t seem to have been successful. Israel’s rejoinder came Tuesday evening with a missile strike in the Hizbollah stronghold of southern Beirut. The strike destroyed a multi-storied building and killed Fuad Shukr, a member of Hizbollah’s leading Jihad Council, the commander of the group’s missile programme and one of its most seasoned veterans. Dozens of others were also reportedly injured in the attack, with more deaths likely. Israeli officials announced that the strike would be their sole retaliation, but also warned that while they did not seek war with Hizbollah, they were prepared for one. Israel had opted for a surgical strike instead of a major bombing campaign, but the targeting of a prominent leader would not be something Hizbollah could simply absorb.

Hours later, Iran’s Islamic Revolutionary Guards Corps (IRGC) announced that Ismail Haniyeh, the leader of Hamas’s political wing, was assassinated in Tehran. Haniyeh had been in Tehran, along with dozens of other foreign dignitaries and representatives of Iran-backed militant groups, to attend the inauguration of President Masoud Pezeskhian. Haniyeh was reportedly killed either by an explosion that struck the exterior of the governmental compound in which he was staying, perhaps delivered by a quadcopter drone, or by some other means. That the prominent Palestinian official could have been targeted in such a highly-secure environment was shocking. Iranian officials quickly blamed Israel for the killing and vowed revenge.

The assassinations in Beirut and Tehran, along with the strike in the Golan, are all part of a complex Middle East war that has been gradually building steam for decades. This war is best understood as an intersection of two separate but related conflicts: one between Israel and the Palestinians, and the other between Israel and Iran. Both conflicts played out in tandem but have increasingly crossed over to a point that since 7 October  2023, they have been difficult to disentangle.

In response to the war in Gaza, Iran-backed groups across the region began targeting Israel with rocket, drone, and missile strikes. Hizbollah has been the most active in this regard, and its attacks have forced thousands of Israelis to flee their homes in the north. Israel has also endured numerous missile and drone attacks from the Houthis in Yemen, including a strike on 19 July that hit an apartment building and killed an Israeli civilian.

Israel has waged a counter-campaign against Iran and its allies, leading to scores of strikes against Hizbollah, IRGC, and Iran-backed proxies in Lebanon and Syria, and a significant attack on fuel storage in the Houthi-controlled Yemeni port of Hodeidah. Israel has also pursued a longstanding covert campaign inside Iran, which has included industrial sabotage and the assassination of military officials.

Despite Israel’s forward-leaning effort, the country remains encircled by Iran-backed militant groups armed with advanced aerial weaponry. The weapons used by Hizbollah and the Houthis to target Israeli population centres are all supplied by Iran, which also assists its militant allies with funding, logistics, and intelligence. In that way, Israel has been fighting a multipronged conflict, in many ways fuelled and orchestrated by Iran. Although the attacks of the last year have been ostensibly in response to the war in Gaza, all of these groups, and Iran, seek the destruction of Israel as a Jewish state. By staking out such an uncompromising position, Israel’s options for dealing with its external enemies are limited. It can either live with the aggression and allow Iran to make these groups stronger, or it can try to weaken them bit by bit.

An all-out war is also a possibility, but not something that clearly favours either side. Iran and its allies cannot bring the war to Israel. They don’t have the means, and even if they had the will, the United States and Israel’s other European allies would inevitably intervene. War is not a simple solution for Israel either. Israel lacks the military strength to sustain a bilateral war against Iran on its own, and a war in Lebanon against Hizbollah – whose weapons stockpile is buried deep below Beirut and other urban strongholds in intricate and sophisticated tunnel networks – would be orders of magnitude more difficult than the current campaign in Gaza. Some in Israel’s political establishment might pine for the United States to lead an effort against Iran and its proxies but successive administrations have shown little interest in war with Iran, and the current White House is unlikely to pursue such adventurism in an election year.

A greater war, such as the one that took place in Lebanon in 2006, is also something that Hizbollah and Iran are likely to want to avoid. After decades of mismanagement, corruption, and political deadlock, Lebanon is on the brink of economic and social collapse. A war would thrust the country into a crisis that it might not easily escape from. Total disintegration of the Lebanese state would jeopardise Hizbollah’s place within it and could trigger unpredictable domestic upheaval. Hizbollah benefits from Lebanon’s dysfunction but it could not easily navigate a complete breakdown of the present order, as ramshackle as it might be. Furthermore, war would be inherently damaging to Hizbollah and degrade its military strength. Even if it were to survive the conflict, there is no promise that Hizbollah could return its capabilities to pre-war levels, much less that it could do so quickly.

For Iran, the risks are just as great. With Hamas and Palestinian Islamic Jihad heavily damaged in Gaza, Hizbollah remains Iran’s main leverage point with Israel. Were Hizbollah to be similarly weakened, Iran’s ability to organise coercion against Israel would correspondingly falter. Iran maintains militias in Syria and Iraq, who, along with the Houthis in Yemen, are able to target Israel with missiles and drones, but those militias are distant shadows of Hizbollah and lack the group’s cohesion, discipline, and military acumen.

AsIran’s entire regional strategy rests on encircling Israel with allied militias, a severely degraded Hizbollah, alongside the effective loss of Hamas, could significantly diminish Iran’s ability to achieve its ambition of overturning the regional order. A war against Hizbollah could harm Iran’s agenda and Iran’s leaders might consider such a war too important to fight by proxy, and could intervene on Hizbollah’s behalf. But any Iranian military action against Israel runs the risk of inviting American counter-intervention, which would further impair the likelihood of success for Iran and its allies.

In other words, each party in the present crisis has incentives to limit the escalatory cycle and prevent an all-out war from breaking out. It is perhaps for these reasons that, so far, Hizbollah, Israel, and Iran, have settled into the current pattern of tit-for-tat violence. That cycle has kept the conflict at a slow boil but has done nothing to alter its course. Hizbollah and Iran can either respond to the latest attacks in a fashion that seeks to maintain the precarious status quo, or they can up the ante, and risk pushing the conflict into a more furious direction. What is unlikely to occur is a settling of differences. The only way to avoid a deepening war is for the region’s actors to adopt fundamentally different goals, and for their leaders to make fundamentally different choices. Until there is the will for change, the perpetuation of conflict is inevitable.