The naval base at Simonstown, perched at the tip of Africa, has returned to global relevance as Houthi attacks on commercial shipping in the Red Sea have driven much of Europe–Asia trade away from the Suez Canal and around the Cape.

The chaos and risk in the Red Sea has forced global shipping giants to choose the much longer southern detour, turning the waters south of Cape Town into the world’s busiest alternative sea route. This has transformed what was once a relatively peripheral stretch into a strategic corridor, with the Cape’s narrow navigable channel, which is bound by the Agulhas Bank and fully within South Africa’s exclusive economic zone, suddenly thrust back onto the front line of global maritime security.

Simonstown naval base has always been the nerve centre for South Africa’s sea power. Established in the 19th century to anchor British imperial interests, the base supported Allied convoys and anti-submarine operations during both World Wars, and monitored Soviet naval activity through the Cold War.

Its partnership with Western navies was formalised during the Cold War under the Simonstown Agreement, making it a linchpin in the defence of the Atlantic and Indian Ocean sea routes. The sheltered harbour, proximity to shipping lanes, and deep-water anchorage made Simonstown indispensable to maritime security in the region.

Strategic reckoning

The 21st century has forced a strategic reckoning. As the Suez Canal’s vulnerability is exposed by proxy warfare and piracy, the Cape route has become more critical than at any point in the past 50 years. Blockades, sabotage, and missile attacks in the Red Sea by Iran-backed Houthi militias have repeatedly forced international shipping southwards. Yet the South African Navy is no longer fit to police this artery.

Years of underfunding, political drift, and eroded technical capability have left Simonstown with a diminished fleet and declining readiness. Merchant vessels now actively avoid refuelling or refitting in South Africa due to its failing ports, with the World Bank ranking local ports among the least efficient worldwide.

This vacuum is not theoretical. In 2007, during modern naval war games, a single South African submarine operating out of Simonstown demonstrated the ability to “sink” every participating ship in a NATO exercise, a reminder of the tactical leverage afforded by familiarity with the Cape’s treacherous currents and undersea topography. But in practice, South Africa’s operational capabilities have deteriorated.

Silvermine, the subterranean intelligence hub supporting Simonstown, once coordinated NATO-wide maritime surveillance, but now primarily houses civilian operations and rescue coordination. The result is a base with immense historic and geographic advantages, but shrinking ability to defend, deter, or project power.

Global implications

The global implications are hard to miss. With China, Russia, and the West competing for access and leverage over the world’s sea lanes, the global power exerting the most control over the Cape passage holds an irreplaceable card in the game of global trade and security. Instead of allowing Simonstown to languish, the South African government could leverage this naval base as a strategic asset with which to win trade and investment concessions from the world’s most powerful nations using its geographic position as bargaining power in a shifting global order.

Mahan, a United States Navy admiral and historian, argued that the fate of great powers was decided not on land, but at sea. “Control of the sea by maritime commerce and naval supremacy means predominant influence among the nations; it has been so in the past, and it will be so in the future,” he wrote in 1890.

Mahan will be a regular column examining contemporary geo-politics.