In recent weeks, millions of Israelis have been awoken in the night and forced into bomb shelters due to incoming missiles — not from Gaza, Lebanon or Iran, but from Houthi militants in Yemen.

With Hamas, Hizbollah and the Islamic republic itself all weakened and humbled after 15 months of conflict with Israel, the Houthis have styled themselves as the Palestinians’ main regional defenders and the final bastion of Iran’s so-called “axis of resistance” still attacking Israel.

Despite morbid jokes on Israeli social media calling them the country’s new “alarm clock”, the Houthis have become a painful reminder for Israelis that the war is not over. Their ballistic missiles have twice evaded air defences, injuring 16 people in the Tel Aviv area.

“I call them ‘the last proxy,’” said Amos Yadlin, a former head of Israeli military intelligence. “It took the Israeli system time but now it’s well understood . . . they need to be moved to the top of the priority list.”

Israeli officials say they will do just that, launching multiple long-range air strikes on Yemen, the most recent of them targeting ports and power stations on Friday. “The Houthis are paying, and will continue to pay, a heavy price for their aggression against us,” Prime Minister Benjamin Netanyahu said.

But analysts and former officials warn that the Houthis, situated 2,000km away, are a vastly different and more complex challenge than adversaries closer to home.

The battle-hardened Islamist movement controls northern Yemen and endured a years-long Saudi-led bombing campaign during the country’s civil war.

In the wake of Hamas’s October 7, 2023 attack, the Houthis began firing on merchant ships off the Yemeni coast and launching armed drones and missiles at Israel, saying they were acting in solidarity with Palestinians. Their assaults severely disrupted shipping through one of the world’s most important maritime trade routes and effectively closed Israel’s port of Eilat.

A naval task force led by the US and UK has so far been unable to halt the fire, despite bombing Houthi weapons platforms and command centres.

“The [international] coalition wasn’t able to deter the Houthis . . . and initially from October 2023 there was no response from Israel,” said Ely Karmon, a senior researcher at the International Institute for Counterterrorism at Reichman University.

Unlike Hizbollah, Hamas, Syria or Iran, the Houthis had not been a priority for Israeli military and security services, according to one person familiar with the matter, and intelligence on them had been “close to zero” before October 7. Rectifying this would “take time”, they added.

Since last summer, Israeli warplanes have struck Yemen directly on five occasions, starting with Hodeida and other maritime gateways, followed by power stations further inland and now the capital Sana’a — including the international airport.

Each such operation, some of the most far-ranging in Israeli air force history, required several dozen fighter jets and mid-air refuellers — vastly more complex than the short sorties required in neighbouring Gaza, Lebanon or Syria.

Though the Israeli bombing raids have been painful and expensive for Yemen — especially the destruction in Hodeida, a vital artery for supplies into the populous north — Yemeni analysts say they have not deterred the Houthis or dealt significant military blows.

Mohammed al-Basha, founder of the Basha Report risk analysis newsletter, said the group was able to decentralise oil imports away from large fuel depots directly to trucks, while most households in Sana’a receive electricity from private sources. Flights at Sana’a airport resumed shortly after an Israeli raid last month.

Yet the toll will probably be paid by the Yemeni people — especially if food imports are curtailed and the price of fuel rises.

“The main impact is humanitarian . . . it doesn’t weaken the Houthis, and doesn’t really bother them as they don’t really care about what happens to civilians,” said Abdulghani Al-Iryani, a senior researcher at the Sana’a Center for Strategic Studies.

But by boosting the group’s profile, the attacks against Israel have helped the Houthis deflect attention away from issues at home.

The Palestinian cause “is the only thing they get popular support for in Yemen or elsewhere”, Iryani said. “The heroic posturing is very attractive and people are cheering them on, regardless of the costs.”

Israel seemingly intends to test how much pain the Yemeni people, and by extension the Houthis, are able to absorb. Several Israeli analysts said that escalating strikes on key state infrastructure such as ports and energy facilities are probable, while halting weapons smuggling routes from Iran is also a priority.

“There’s no organisation in the world responsible for territory that can’t be deterred,” said Yadlin, adding that incoming US president Donald Trump might provide Israel with a freer hand in this regard.

Some in Israel argue the goal should be toppling the Houthi regime by providing military support to the group’s adversaries and factions loyal to Yemen’s internationally recognised government in the south.

Direct Israeli engagement in a Yemeni civil war would have a historical precedent. Israel’s Mossad security agency and its air force assisted British intelligence services and special forces in the so-called “covert war” in Yemen in the 1960s, arming royalist forces against Egyptian-backed republicans.

Israeli officials have also said that Houthi leaders are now a target for assassination, particularly the group’s commander, Abdul Malik al-Houthi.

Karmon, one of Israel’s foremost Houthi experts, argues that the elimination of the charismatic Abdul Malik would lead to the “disintegration of the group’s rule”.

But targeting its leaders and missile arsenals will not be easy.

Analysts believe Abdul Malik is likely to be in Yemen’s far north, in the mountainous Houthi stronghold of Saada. But accessing Saada — for both regular Yemenis and foreign spy agencies — is extremely challenging for anyone but locals, Basha said.

“No matter how strong an army is, no matter how sophisticated it is, you can’t bomb the hell out of a mountain,” said Farea al-Muslimi, a research fellow at the Chatham House think-tank. He added that a century’s worth of attempts to bomb local fighters into submission had failed.

“The Ottomans tried it, the Egyptians tried it, the Saudis tried it, the Emiratis tried it. Force doesn’t make a difference . . . you cannot force them.”

Cartography by Steven Bernard