A sudden military escalation in Yemen has shattered a fragile, informal four-year truce, threatening to expand an ongoing geopolitical conflict into the Red Sea and sever one of the world’s most vital energy arteries.

Following days of heightened rhetoric, Yemen’s internationally recognised government bombed the runway at Sanaa International Airport on Monday to prevent an Iranian aircraft from landing. In swift retaliation, Houthi rebels fired ballistic missiles towards southern Saudi Arabia, accusing Riyadh of being behind the attack on the airport — and declaring that the era of de-escalation with Yemen’s larger neighbour was officially over.

While the immediate violence centres on the airport dispute, analysts warn that the true danger lies in how this localised flare-up could spill over into the Bab al-Mandeb Strait, if it expands.

The Sanaa airport flashpoint

The trigger for the latest crisis highlights the deep regional fault lines running through Yemen. The Yemeni government, backed by a Saudi-led coalition, justified its strike on the airport by claiming the Iranian flight was carrying military experts, drone technology, and communication equipment.

Houthi officials on the other hand have insisted the aircraft was transporting over 200 stranded medical patients alongside a delegation returning from the funeral of the late Iranian Supreme Leader Ayatollah Ali Khamenei in Tehran. The Houthis ultimately diverted the flight to Hodeidah and responded by launching ballistic missiles at Saudi Arabia’s Abha International Airport, which the Saudi-led coalition said it intercepted.

A two-front maritime chokepoint

The resurgence of violence in Yemen comes at a precarious time for global trade. With Iran effectively closing the Strait of Hormuz again amid its ongoing war with the United States and Israel, the Bab al-Mandeb has become a critical pressure point.

“The Yemen situation, or the entire Bab al-Mandeb region, has been on a powder keg from the first day of the war,” said Ibrahim Fraihat, a professor of international conflict resolution at the Doha Institute for Graduate Studies, to Al Jazeera, noting that the “spillover” of the conflict into surrounding areas was inevitable.

For Tehran, shifting focus to the Red Sea offers a strategic counterweight to Washington’s naval blockade in the Gulf. Ali Akbar Velayati, a senior adviser to Iran’s supreme leader, has warned more than once that the “axis of resistance” — an Iran-backed coalition that includes the Houthis — has the capability to block both waterways.

Mohammad Cherkaoui, a professor of international conflict resolution, warned that as American pressure and the naval blockade increase on the Strait of Hormuz, Iran might seek to find a new outlet through its regional allies. “If the Bab al-Mandeb crisis erupts in parallel with the Hormuz crisis, we will face a pincer movement that blows away the stability and security of the Gulf,” Cherkaoui told Al Jazeera.

This strategy appears to be calculated. Mohammad Saleh Sedghian, director of the Arab Centre for Iranian Studies, pointed to recent remarks by Esmail Qaani, the commander of Iran’s Quds Force, who spoke of forming “a belt between the Strait of Hormuz and the Bab al-Mandeb” to protect the axis of resistance.

The ‘Gate of Tears’

Historically known in Arabic as the “Gate of Tears” due to the historical dangers of navigating its narrow waters, the Bab al-Mandeb Strait is a 29km (18-mile) bottleneck connecting the Red Sea to the Gulf of Aden and the Indian Ocean.

Roughly 12 percent of global trade passes through it daily, including heavily laden container ships travelling between Asia and Europe.

Crucially, the strait is a massive energy corridor. In 2024, oil trade flows through the Bab al-Mandeb averaged 4.0 million barrels per day. It serves as an essential route for moving crude oil, refined petroleum products, and liquefied natural gas (LNG) towards European and North American markets.

The closure scenario

With traffic barely passing through the Strait of Hormuz amid the recent escalation in fighting between the US and Iran, a closure of the Bab al-Mandeb would be catastrophic for global energy markets.

Iran has declared the Strait of Hormuz closed, and US President Donald Trump has reimposed a naval blockade on all Iran-linked ships trying to pass through that waterway.

If the Bab al-Mandeb and the Strait of Hormuz were shut simultaneously, approximately 25 percent of the world’s total oil and gas supply would be blocked. Ships would be forced to reroute around the southern tip of Africa via the Cape of Good Hope, adding 10 to 14 days to delivery schedules. This detour would send shipping and insurance costs skyrocketing, triggering a severe global economic shock.

“If the Houthis decide to respond, believing Saudi Arabia started this… it will lead to greater escalation, and I am even more concerned about maritime navigation in the Red Sea,” Bill Putnam, former commander of the US Military Intelligence Readiness Command, told Al Jazeera.

Threatening the Saudi bypass

A closure of the Bab al-Mandeb would also neutralise a major strategic advantage held by Saudi Arabia.

Unlike its Gulf neighbours—such as Kuwait, Bahrain, Qatar and the UAE, whose energy exports are largely trapped by the closure of the Strait of Hormuz—Saudi Arabia has to an extent successfully circumvented the blockade using its East-West Pipeline.

The 1,200km (745-mile) pipeline, operated by Saudi Aramco, links the Abqaiq oil facilities in the east to the port city of Yanbu on the Red Sea. Recently restored to its full capacity of 7 million barrels per day following attacks, this pipeline has allowed Riyadh to safely export massive volumes of crude away from the contested waters of the Gulf.

However, exporting from Yanbu relies entirely on the Bab al-Mandeb remaining open for ships travelling south to Asian markets. If Houthi forces follow through on their threats and lock down the Red Sea chokepoint, Saudi Arabia’s successful bypass would be rendered useless, trapping its oil alongside that of its neighbours and plunging the global economy deeper into crisis.