13th September 2026
There are moments in international affairs when a relatively small geographical development suddenly becomes important to almost everybody. The latest advance by Yemen's Houthi movement may be one of them.
The Iran-aligned Houthis have rapidly expanded their control along Yemen's Red Sea coast, capturing the strategically important port of Mocha and moving into the Bab el-Mandeb area. They have also taken control of Mayyun, or Perim, Island, which sits in the middle of the narrow strait linking the Red Sea with the Gulf of Aden.
This is not simply another episode in Yemen's long-running civil war. Bab el-Mandeb is one of the world's most important maritime chokepoints. What happens there can affect the price of oil, the cost of shipping, insurance premiums, inflation and ultimately the prices paid by consumers thousands of miles away.
For Britain, that includes the price of petrol and diesel and potentially the cost of many imported goods.
The geography suddenly matters
Bab el-Mandeb is only about 29 kilometres wide at its narrowest point. It is the southern gateway into the Red Sea. From there, ships can travel north through the Red Sea and the Suez Canal before entering the Mediterranean.
That route is enormously valuable because it saves ships travelling between Asia and Europe from having to sail around the Cape of Good Hope.
But the waterway is now becoming increasingly dangerous. The Houthis had already demonstrated since 2023 that they could make shipping companies think twice about using the Red Sea. Attacks on commercial vessels caused much of the traffic to be diverted around Africa.
Shipping through the Red Sea subsequently fell dramatically. Now the Houthis have moved closer to the physical chokepoint itself.
That changes the calculation as they do not necessarily need to close the strait completely. If shipping companies believe that passing through it carries an unacceptable risk of missile attack, drone attack, mines or other forms of disruption, ships can simply take another route.
That is what makes this form of warfare so powerful.
Control does not necessarily mean closing the strait
There has been some dramatic reporting suggesting that the Houthis now “control” Bab el-Mandeb.
That needs some qualification. The Houthis do not have uncontested control of every ship entering the strait and they are not a conventional naval power capable of enforcing a complete blockade in the traditional sense.
What they have gained is something potentially more important: the ability to threaten shipping from a much stronger geographical position.
The capture of Mayyun Island gives them a position close to the centre of the waterway, while control of stretches of the Yemeni coastline gives them additional opportunities to use missiles, drones and other weapons against shipping.
That creates uncertainty and uncertainty is expensive.
The timing could hardly be worse
The Red Sea problem is particularly serious because the other great Middle Eastern maritime chokepoint, the Strait of Hormuz, is already severely disrupted.
Hormuz is the gateway through which a huge proportion of the world's oil normally passes. Recent vessel-tracking data showed traffic through Hormuz falling to only seven vessel movements in one day, compared with a ten-day average of 14.
That means the Bab el-Mandeb has suddenly become even more important.
If one route is severely restricted, alternative routes become more valuable.
If both are threatened at the same time, the world's energy system becomes considerably more vulnerable.
Reuters estimates that a closure or serious disruption of Bab el-Mandeb could affect up to 7 per cent of global oil flows and around 12 per cent of global trade.
Those figures should not be interpreted as meaning all of that trade would suddenly disappear.
Ships can reroute. Oil can sometimes be moved through pipelines. Strategic reserves exist. And markets adjust. But none of those alternatives is free.
The Cape of Good Hope is a very expensive detour
If shipping companies decide that the Red Sea is too dangerous, vessels travelling between Asia and Europe can sail around the Cape of Good Hope. That adds thousands of miles to some journeys. It means more fuel. It means ships and crews are tied up for longer and it reduces the number of journeys a vessel can make each year.
Insurance costs rise and eventually those additional costs find their way into the prices of goods.
This is one reason a conflict thousands of miles from Britain can eventually appear in a supermarket price or a delivery charge. The economic effect is not necessarily immediate. It works its way through supply chains.
A manufacturer pays more for transport. The wholesaler pays more. The retailer pays more. The final customer eventually sees some of that increase.
Then there is oil
Oil is potentially the most sensitive part of the story. Brent crude has already moved above $100 a barrel amid the wider Middle East crisis.
The latest Houthi advance has added another source of uncertainty to an already disrupted oil market. Markets do not need to lose every barrel of oil to push the price higher. They only need to become worried that future supplies could be disrupted. That is the crucial difference between physical shortage and risk premium.
If traders believe there is a serious possibility that supply will be interrupted, they can bid up prices before the shortage actually happens.
That is why geopolitical events can affect petrol prices almost immediately. Saudi Arabia faces a particularly difficult problem
The situation is especially uncomfortable for Saudi Arabia. The kingdom has spent years developing alternative ways of moving oil that could bypass Hormuz. Its East-West pipeline can carry Saudi crude towards the Red Sea, allowing oil to reach the global market without travelling through Hormuz.
But that alternative is now under pressure too.
Saudi Arabia has shut the pipeline after drone attacks on pumping stations, while the Houthi advance threatens the Red Sea route itself.
In effect, some of the escape routes from one chokepoint are now becoming vulnerable to another.
That is what makes the present situation particularly dangerous.
Iran's strategic position has strengthened
This is where the wider geopolitical significance becomes apparent. Iran does not need to send its own navy into the Red Sea to create problems there.
Its relationship with the Houthis gives it influence through a regional force that has its own military capabilities and its own objectives.
It would be wrong to portray the Houthis as simply Iranian puppets. They have their own Yemeni political and military agenda.
But Iran's support and relationship with the movement means Tehran can exert pressure on another critical maritime route without necessarily taking direct responsibility for every action.
That complicates any American response.
If Washington attacks the Houthis heavily, the conflict could widen. If it does little, the Houthis may consolidate their position.
The United States is therefore faced with an awkward choice at a time when its military resources are already heavily committed elsewhere in the region. Reuters reports that Saudi Arabia has asked for greater American military support, while Washington has so far concentrated on intelligence and other assistance rather than launching a major new intervention.
This is not just about America
It would be easy to describe this as another confrontation between America and Iran. But the consequences are global.
European shipping depends heavily on the Suez route. Asian exporters depend on access to European markets. Energy markets operate internationally. Insurance companies price maritime risks globally.
And Britain's economy remains heavily dependent on international trade. That means the consequences could eventually reach Britain even if not a single British ship is attacked.
What could happen next?
There are several possibilities. The least damaging would be that the Houthi advance produces a new round of negotiations and an agreement that allows commercial shipping to continue safely.
Another possibility is a prolonged period in which shipping companies use the Red Sea selectively, with war-risk insurance and freight costs remaining high.
The more serious scenario would be sustained attacks on commercial shipping combined with continuing disruption in Hormuz.
That could produce another major oil-price shock.
And there is an even more dangerous possibility: direct American or Saudi military action against the Houthis followed by retaliation against shipping or energy infrastructure elsewhere in the region.
That could turn what is currently a series of interconnected regional conflicts into a much wider confrontation.
Why Britain should be paying attention
For British households, all of this can sound remote. It isn't.
Britain imports enormous quantities of goods. It imports energy. It depends upon global shipping. Its economy is already dealing with inflationary pressures and higher borrowing costs.
A sustained increase in oil prices would put upward pressure on petrol, diesel, transport and production costs.
That could push inflation higher. And this is where the story connects with another problem already affecting households: interest rates.
If energy prices push inflation higher, the Bank of England has less freedom to cut interest rates.
Financial markets may also push up bond and swap rates if investors believe inflation will remain higher for longer. That can feed directly into fixed mortgage rates.
In other words, the chain can run from a small island in the Bab el-Mandeb to a British household's mortgage.
The real threat is uncertainty
The most important point is that the world does not need to see a complete closure of Bab el-Mandeb for the economic consequences to be serious. Shipping companies only need to decide that the risk is too high. That is the power of a strategic chokepoint.
The Houthis have now acquired a much stronger position beside one of the world's most important maritime routes. Iran gains additional strategic leverage. Saudi Arabia faces pressure on both its oil export routes and the security of its southern approaches. The United States faces another difficult military and diplomatic calculation.
And the rest of the world watches the price of oil, shipping and insurance.
For Britain, the lesson is uncomfortable. We often think of globalisation as meaning goods can move almost effortlessly around the world. They cannot.
Much of world trade passes through a surprisingly small number of narrow waterways.
Hormuz. Bab el-Mandeb. Suez. Panama.
Block or threaten enough of them and the consequences spread far beyond the battlefield.
The Houthis do not need to stop every ship.
They may only need to make enough shipowners decide that the safest route is the long way round.
And if that happens at the same time as Hormuz remains under pressure, the economic consequences could be considerably greater than the headlines about Yemen initially suggest.