Did Trump leave his allies to face the Houthis alone?

This is a form of "conflict compartmentalisation", in which a major power separates the theatre that directly threatens its own interests from the wider war, then manages each arena through a different instrument.  Washington is trying to prevent several confrontations from merging into a single conflagration, so it reserves its military force to protect its own troops, uses negotiations to safeguard its shipping, and provides intelligence support to its allies.

Domestic considerations likely figure greatly into Trump's compartmentalisation strategy, as he struggles to retain control of at least one chamber of Congress in the November elections. His Democratic opponents are using the war as a campaign issue that could cost him congressional control and leave him politically constrained, potentially turning him into a "lame duck" president if he loses control of both chambers of Congress.

To voters, strikes against a group in response to an attack on American ships or servicemen are far easier to justify than entering a complex Yemeni civil war to help an ally, especially after two decades of open-ended US wars in the Middle East.

Trump has also previously restrained Israeli Prime Minister Benjamin Netanyahu from expanding the war in Lebanon and prevented him from striking Iran, in keeping with understandings reached with Tehran under a memorandum of understanding that the US has since abandoned, although indirect contacts have continued through intermediaries. Trump hopes to secure a new preliminary agreement with Iran before the elections, present it to American voters as a political achievement, and put his Democratic opponents on the back foot.

The White House has refined its thinking about when direct military intervention is warranted. To understand that shift, we need to return to the 2025 campaign. When Houthi attacks threatened US shipping and navigation in the Red Sea, the Trump administration launched a major military operation. At the time, Defence Secretary Pete Hegseth said its purpose was to halt attacks on assets operating through the corridor and restore freedom of navigation, which he described as a "core national interest of the United States".

Vance later explained that the administration had entered the conflict with a narrowly defined objective: to compel the Houthis to stop attacking US vessels while avoiding entanglement in a prolonged war with a non-state armed group.

Once Trump secured the commitment he sought, he ended the campaign. In May 2025, he said the Houthis had informed Washington that they would no longer attack American ships. Oman confirmed that the agreement stipulated that neither side would target the other, including US vessels in the Red Sea and Bab al-Mandab.

Israel was not explicitly named. Yet the available information indicates that the Houthis themselves undertook to refrain from attacking Israeli targets and have since observed that restraint. Their conduct has been consistent with Tehran's own decision not to target Israel during the latest rounds of fighting. Israeli sources have also said that their vessels now pass through Bab al-Mandab under the eyes of Houthi forces without coming under fire. The Houthis' war against Saudi Arabia likewise accords with Tehran's focus on pressuring Riyadh through its allies in Iraq and Yemen.

For Trump, success in war does not mean eliminating the Houthis, rebuilding Yemen, or engineering a new regional balance. His overriding objective is either to defeat Iran or to reach a political settlement that secures the same central aim: compelling Tehran to abandon its military nuclear programme.

Trump's refusal to intervene does not mean that the White House underestimates the gravity of the recent developments. Houthi control of new positions near Bab al-Mandab—one of the world's most important maritime passages—gives the group tremendous leverage at a time when its chief ally, Iran, is also exerting pressure on shipping through the Strait of Hormuz. Saudi territory has come under missile and drone attack, while the East-West Pipeline, the country's principal route for exporting oil after the effective closure of the Strait of Hormuz, has also been targeted.

Tough spot

The White House reported that Trump did consider strikes but then decided against them after his advisers reportedly expressed reservations that US military involvement could widen the war and give reasons to the Houthis to completely close Bab al-Mandab or resume attacks on American vessels. Also, if Trump strikes the Houthis, he runs the risk of dragging the US into another war with no clear exit.

This was a lesson the US learned in its 2025 military campaign against the Houthis. While the operation inflicted serious damage on the Houthis, it failed to destroy their capabilities, and they retained their ability to fight. Later assessments indicated that the campaign consumed costly munitions, including the downing of two aircraft and several drones. 

Since then, Yemen's recognised authorities have reorganised their forces, incorporating armed Yemeni groups that had suffered under Houthi rule and building up their own air capabilities, including drones and combat aircraft. Although they lost their most recent battle around Mocha, they succeeded in repelling Houthi attacks and advances elsewhere, including in Marib, where Yemen's oilfields are concentrated.

Although there is no formal defence treaty between the US and Saudi Arabia, military cooperation between the two has been continuous. US sources have confirmed that the Trump administration offered intelligence sharing and help with target identification, stopping short of direct strikes. The US has also reportedly assisted Yemeni forces in planning, command, and control, as well as efforts to integrate the various Yemeni formations opposed to the Houthis.

A strategic relationship cannot be judged solely by whether US aircraft take part in bombing missions. Intelligence sharing, early warning, air defence, target identification, weapons supplies, and spare parts are all instruments of military power.

Consistent policy

US approval to sell Saudi Arabia 48 advanced fighter jets—something it has not even done for its close allies Türkiye and the UAE—demonstrates solid mutual trust. So Washington's decision not to enter the fight militarily should not be read as a rift, but as risk-distribution. Saudi Arabia and its allies bear the dangers of a war that directly concerns them, while the US provides the tools intended to strengthen their capabilities and limit their losses. The policy is consistent with the principle of 'burden-sharing', under which an ally assumes primary responsibility for defending its own territory and interests.

The same logic has shaped Trump's handling of the war with Iran. When Tehran attacked US targets and interests, he was prepared to use force directly. Yet he has been unwilling to give Washington's allies unlimited latitude to continue military operations when he believes those operations could jeopardise his diplomatic track.

This became clear in his dispute with Netanyahu over Lebanon. Trump pressed Israel to halt its attacks and avoid widening the war with Hezbollah after Tehran concluded that continued strikes against its allies would undermine any prospective agreement. Iran warned that it would resume its attacks if Israel continued targeting Hezbollah.

Reuters reported that Trump sharply rebuked Netanyahu and persuaded him to abandon a plan to strike Beirut in an effort to preserve the possibility of an agreement with Iran. The episode sparked an uproar inside Israel, where Netanyahu's opponents argued that he had allowed the US to restrict Israel's freedom of military action.

In Yemen, the calculation is similar. A new US campaign against the Houthis—Iran's most powerful remaining proxy and the one best placed to threaten major shipping lanes—could, in Trump's view, derail diplomacy and once again bring together the fronts he has been trying to keep separate.

Risk of ambiguity

But Trump's ambiguity, and at times his inconsistency, carries a risk of its own. The Houthis could interpret US restraint as a green light to continue their expansion. US insistence that it retains the right to strike at any time could help deter the Houthis from crossing some lines.

Trump's broader objective may be to place the conflicts in Yemen, Lebanon, and Iran within a single strategy aimed at reducing the scale of the war and opening the way to a settlement with Tehran. That would explain his efforts to prevent Netanyahu from widening the war in Lebanon and his reluctance to open a new US front against the Houthis, either of which could jeopardise the diplomatic track.

However, this policy carries a genuine strategic risk. If Iran and its allies conclude that avoiding US targets is enough to keep Washington on the sidelines, they may direct greater pressure towards US partners. Separating the fronts could then shift the cost of war from the US to its allies rather than contain the conflict.