To grasp the importance of the Red Sea, visit Djibouti. Before missiles fired by Yemen’s Houthi rebels reduced cargo shipments by more than two-thirds in 2024, about 12% of global trade passed by the former French colony. Both America and China have their only permanent military bases in Africa at this strategic spot on the African side of the Bab al-Mandab strait, where the Red Sea meets the Gulf of Aden (see map). France, Japan and Italy all have bases there. Warships from countries as diverse as Greece and Iran drop anchor at Djibouti’s docks. “Djibouti is a haven of stability,” says Slim Feriani, who runs the country’s sovereign-wealth fund.

That stability makes it exceptional in the Horn of Africa. “The whole region is on fire,” says Mohammed Idriss Farah, a veteran Djiboutian diplomat. He does not just mean the Houthis’ attacks on commercial shipping. Sudan is being torn apart by a catastrophic civil war, now in its third year. Somalia is disintegrating. Tensions between Eritrea and landlocked Ethiopia are rising. Though each crisis is driven by different, home-grown causes, “the question of who controls the Red Sea and who will guarantee its security” is common to them all, says a foreign-policy strategist at a government think-tank in Djibouti. In an increasingly multipolar world, that question is likely to foment more instability.

Until fairly recently, geopolitical competition in the Red Sea, particularly between the United Arab Emirates (UAE), Saudi Arabia and Egypt, was kept in check by the “traffic cop of last resort”, as Alex Rondos, a former EU special representative to the Horn of Africa, describes America. Under Donald Trump, America has bolstered its naval presence in the Red Sea in order to bomb the Houthis. But it is said to be considering pulling out of Djibouti and cutting support for Somalia’s fight against jihadists. The resulting instability means that peaceful commercial and geopolitical competition is increasingly escalating into something darker.

Nowhere is this more evident than in Sudan, which has more than 800km of coastline. Turkey and Qatar signed deals to build and manage commercial ports there in the 2010s. In 2022 an Emirati consortium agreed on a $6bn port and agriculture project. Russia has its eyes on Port Sudan, in a bid for its first military foothold on the Red Sea. Iran, which used ports in Sudan to smuggle arms to the Houthis in the 2010s, has similar ambitions.

With the onset of civil war in Sudan in 2023, the competition turned violent. The rival foreign powers funnelling arms and money to Sudan’s warring parties are doing so at least in part to secure their Red Sea interests. Russia has reportedly reached an agreement with Sudan’s national army to set up a naval base in Port Sudan. The UAE sends arms to the Rapid Support Forces (RSF), the other main belligerent in the war. That prompted a move by Sudan’s government last year to cancel the port deal. Yet the port will remain a key interest for the UAE, says Jonas Horner of the European Council on Foreign Relations. That could mean increasing support for the RSF to prevent an army victory.

Rivalries in the Red Sea are also tugging at the seams of Somalia’s fragile federation. In 2017, to the ire of the federal government, the UAE invested around $400m in a new container terminal in the breakaway region of Somaliland. Satellite imagery shows it has since built a nearby harbour for military use, as well as similar facilities at the port of Bosaso in Puntland, another separatist region. Turkey, by contrast, supports the federal government, and last year agreed to deploy its navy to police Somalia’s coastal waters. Turkish firms own stakes in Somalia’s ports.

Like the UAE, America is inching closer to Somaliland. American warships have reportedly been stationed off its coast in recent months. Officials in the Trump administration are said to be mulling a new American naval base, perhaps in exchange for recognition of the would-be state. Last month, to head off such a deal, Somalia’s president reportedly offered America “exclusive operational access” to both Bosaso and Somaliland’s Berbera port (despite having meaningful control over neither).

Potentially the most explosive addition to the Red Sea’s harbour rush is Ethiopia. A deal with Somaliland to build a naval base sparked a diplomatic furore last year and has since been put on hold. Yet Ethiopia’s prime minister, Abiy Ahmed, is eyeing his own Red Sea port, the main target being Assab, in Eritrea. Mr Abiy says he does not want war with Eritrea. But few of Ethiopia’s neighbours believe him. Officials in Djibouti suspect that his quest has the backing of the UAE.

For the past few decades outside powers seeking influence in the Red Sea generally did so by leasing harbours from sovereign states. But the Horn of Africa may presage a future in which “supplies and supply chains trump sovereignty and nation states,” says Mr Rondos. Seizing a port is no longer unthinkable.