US options to counter Houthi threat to global shipping

The more intransigent and reckless the Houthis appear before the world, the wider the international consensus on countering them and the greater the diplomatic pressure that can be exerted against them, including applying tough economic sanctions and re-designating them as a terrorist organisation.

Such US diplomatic activity on the Gaza front, if paired with Saudi and/or Omani mediation with the Houthis, might reduce the frequency and intensity of the Houthi attacks, which in return would make the mission of defence at sea more manageable. Under such circumstances, the United States would focus on deterrence by denial by gradually upgrading not just US but collective defences in regional waters.

In the eyes of the Houthis, this US approach will most probably reflect weakness, which is likely to invite more, not fewer, attacks. It also assumes that the United States is nimble enough to gain significant traction on the Gaza diplomatic front, which isn't likely at all given the lack of cooperation of the ultra-right-wing Israeli government.

Option 2: Strikes against Houthi targets inside Yemen

This is the most likely and least bad option. It would signal a level of resolve on the part of the United States and its allies and send a strong message to the Houthis that their aggression will not go unpunished.

The option materialised on Thursday when the US and Britain launched air and missile strikes in Houthi-controlled areas of Yemen, aimed at halting attacks on ships in the Red Sea.

Joe Biden, the US president, said American and British forces, with support from Australia, Bahrain, Canada, and the Netherlands, were involved in the overnight attack, which appeared to target a dozen sites in the country.

In a statement, Biden said: "These strikes are in direct response to unprecedented Houthi attacks against international maritime vessels in the Red Sea – including the use of anti-ship ballistic missiles for the first time in history."

"These attacks have endangered US personnel, civilian mariners, and our partners, jeopardised trade, and threatened freedom of navigation."

Biden also said he would be willing to authorise further attacks on Yemen if Houthi attacks on shipping did not stop. "I will not hesitate to direct further measures to protect our people and the free flow of international commerce as necessary," he said.

With improved intelligence on sensitive Houthi military facilities in Yemen and possibly on Houthi leaders, a US-led coalition (most likely the United States and the United Kingdom) could get lucky and really hurt the effectiveness and coherence of the organisation.

Read more: Can the global economy withstand Houthi attacks on maritime trade?

More than anything else, it would signal to Iran, the chief sponsor of the Houthis, that the United States is willing to severely degrade its key ally in Yemen. That could lead to Iran pumping the breaks on its military support, which would reign in the Houthis.

However, as mentioned before, it's incredibly hard to politically defeat or militarily destroy a deeply rooted, capable, and resilient non-state actor such as the Houthis. It enjoys popular support, both domestically and regionally. Also, should Washington and London pursue strikes against the Houthis inside Yemen, Iran could escalate its support to them or further activate other parts of its regional proxy network, be it in Lebanon, Syria, or Iraq.

The Houthis could escalate, too, and make those regional waters as treacherous as ever, prompting a full-fledged Western military response at a time when resources are stretched too thin and focused on the fight in Ukraine and deterrence in the Indo-Pacific.

Option 3: Military assistance to local resistance

This option recognises that kinetic attacks without boots on the ground have hardly ever defeated or severely degraded a nonstate adversary. The land component is always crucial in such circumstances, to gather accurate intelligence on and directly engage the opponent. That is how the self-styled Islamic State (or Daesh) and al-Qaeda in the Arabian Peninsula were more or less destroyed.  

The challenge with that option, however, is that any attempt to provide extensive and consistent military assistance to local Yemeni agents opposing the Houthis would require the tacit approval and coordination of the Saudis and other regional partners.

But Riyadh will be the first to refuse to sign off on such an engagement for fear of Houthi retaliation. For the Saudis, the fight with the Houthis is over. Calm in Yemen, to continue to pursue critical economic reforms at home, is the Saudis' top priority.

Should there be little to no military support from Riyadh, Cairo, or Abu Dhabi (who all share the same calculus on a confrontation with the Houthis and have decided not to participate in the US-led Operation Prosperity Guardian), Washington and London would have to deploy their own special operations forces to coordinate assistance to local resistance.

That would require an enormous effort of vetting, coaching, and coordinating. It would also take a long time, which Western powers simply do not have, given how urgent the Houthi threat is.

Option 4: Strikes against Iranian targets at sea

If Iran is the supplier of weapons, intelligence, and training to the Houthis, then going after the source of Houthi violence might be the better way to deal with that problem.

This wouldn't necessarily mean bombing targets deep inside Iran, but for both practical and symbolic reasons, it could include striking Iranian military ships and naval assets parked in regional waters that are providing intelligence to the Houthis.

Similar to option 3, this could backfire and lead to Iranian escalation, but it could also work because Tehran knows full well that the United States is dominant conventionally and could sink the entire Iranian navy if it has to.

Iran is a capable power, but it understands deterrence and can act rationally when faced with a serious threat that could impact its overall military capabilities and the security of its regime.

US military force seeking to deter Iran from undermining freedom of commerce and navigation in the late 1980s was effective. So was the killing of top Iranian commander Qasem Soleimani in Iraq by an American drone in January 2020. Iran is not undeterrable.

The question is whether it has enough clout with the Houthis to stop them from launching more attacks against commercial shipping. That remains an open question, but Washington will never know until it tests that proposition.

These are all highly uncertain and bad options, full of risks and variables that are impossible to predict. But the second option of striking Houthi targets inside Yemen is the least bad and possibly most effective. It also just might be the most likely.

I find it incredibly hard to believe that the United States will allow the Houthi attacks to undermine a core and enduring US interest in the region, which also happens to be a public good that impacts the international economy.

The American and British strikes on Thursday could be just the beginning of a larger campaign.