Since the beginning of the year the Royal navy and Air Force have joined the US military in launching a series of strikes against Houthi rebels in Yemen. The strikes have been in retaliation for Houthi attacks on shipping – both merchant and naval – in the Red Sea in recent months.

UK government minister Huw Merriman claimed recently that these airstrikes are not just a “one off”. But while the UK and US have demonstrated their resolve in unitedly countering Houthi belligerence and disruption to global trade by blocking up the Red Sea, Merriman’s statement underlines the risk of being inadvertently drawn into a protracted conflict.

And there is yet to be any evidence to suggest that the Houthis – or other of the myriad Iranian-backed proxy groups in the Middle East – are deterred by western military action as it currently stands.

For almost a decade, the Houthis have been subject to airstrikes by their Sunni rivals in Saudi Arabia and they have proved resilient. Now, with the financial and military backing of Iran, there are no signs that they will end their campaign of disruption in the Red Sea. Houthi commander, Mohamed al-Atifi, has said as much when he recently confirmed that his group is “prepared for a long-term confrontation”.

With military force being used in multiple locations across the region, western resources are stretched at a time when Britain is facing up to a long term decline in military numbers as well as sending huge amounts of military aid to Ukraine. This could turn into something of a bear-trap for both the UK and US.

Western foreign policy in the Middle East has historically been tainted by what some call “mission creep”. A term initially coined by US journalist Jim Hoagland in the 1990s, it’s defined as “a gradual shift in objectives during the course of a military campaign, often resulting in an unplanned long-term commitment”.

The longer the UK remains entangled in fight against the Houthis, the greater the chance that it will be accused of doing just this. Already, the government is facing pressure to limit its involvement. MPs in parliament such as Liberal Democrat leader Ed Davey, have called on the UK prime minister, Rishi Sunak, to give the House “an opportunity to have its say, via a debate and a vote”.

This discernible feeling of angst emanating from Westminster is an outcome of a political environment in the UK, which is still scarred by failures in Afghanistan, Iraq and Libya. Those conflicts have all shown how expanding military objectives can increase regional instability and can contribute to foreign policy failures in the long term, as the resurgence of the Taliban in Afghanistan has proven.

Clarity of purpose

To avoid mission creep, Britain must clearly articulate the specific parameters of its engagement in Yemen. There are three main conditions governing how we come to regard a military engagement as constituting mission-creep. These are: the scope of conflict, as well as the temporal parameters and spatial limits.

Sunak must emphasise that any military action taken will be limited to naval and aerial assaults. Any prospect of ground troops being deployed in the future, would sound alarm bells in parliament. While parliament has no constitutional say in whether a government can send troops to a conflict, such a potentially contentious decision would surely be subject to a democratic vote – as was the case with the intervention in Syria in 2015.

⚓ @HMS_Richmond has taken over from @HMSDiamond in the Red Sea.

The 🇬🇧 remains at the forefront of the response to the illegal attacks from Iranian-backed Houthi rebels and is committed to protecting freedom of navigation.

Read more 👉 https://t.co/N1GZfGXWbE pic.twitter.com/4afTtEjcUQ

— Ministry of Defence 🇬🇧 (@DefenceHQ) February 6, 2024

The PM must also outline a time period as to how long a military operation in the Red Sea would last. This would reassure those who fear getting bogged down in a lengthy conflict. Finally, given the numerous potential theatres of operation at present, Sunak needs to clarify the space in which Britain’s military will operate. He must reassure the country that UK troops will not find their engagement spilling into civilian areas or another state’s sovereign territory.

Past successes and failures

These conditions were not adequately communicated and adhered to by previous governments when deciding to deploy the UK military in the Middle East. In Afghanistan, it set out to remove the Taliban from power in 2001, but then shifted its objective to state-building, which has self-evidently been a failure.

A more successful UK military intervention was in 1995 in Bosnia, where the UK got involved under the umbrella of Nato and Operation Deliberate Force to prevent the further genocide of Bosnian Muslims by the Serb Army. The then defence secretary, Michael Portillo, similarly received questions on the potential dangers of mission creep. He made a statement in the House of Commons in which he stated:

I am determined that the Nato operation will be limited in scope. We have no business inventing one task after another. The important point is that we have a clearly defined job. We shall do it in 12 months, then come home.

Nato’s intervention in the Balkans was considered a strategic success – it resulted in the Bosnian Serb Army limiting their attacks on UN designated safe-zones.

The lack of clarity in Afghanistan meanwhile led to the continuous deployment of British troops, which culminated in 457 fatalities. Meanwhile the part the UK military played in both Afghanistan and Iraq from 2003 severely damaged the country’s reputation for pursuing a competent foreign policy. In part, this was shaped by its failures to withdraw in a timely manner. And it has led to an anxiety which continues to play on the minds of British politicians.

Though the UK’s alliances with the US and other Nato states are key to countering the threat to vital shipping in the Red Sea, the last thing the country needs is another unplanned and open-ended conflict. In 1995, Portillo assured MPs that the UK’s contribution to Nato’s mission in Bosnia would not further compromise the safety of Britain’s soldiers and the region’s stability. The current government needs to do the same when making tough foreign policy decisions about the Middle East.