The contest for maritime dominance in the Indo-Pacific has returned naval strategy to the centre of global politics, and at the heart of this strategic debate stands the ghost of Alfred Thayer Mahan. More than a century after his work revolutionised military thinking, the fundamental ideas set out by Mahan in The Influence of Sea Power upon History, 1660–1783 continue to influence naval policy from Washington to Beijing.

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.

His thesis emerged from a careful study of history, showing that Britain’s rise as the world’s leading power depended on its mastery of the oceans. Mahan’s work became a global bestseller, translated into multiple languages and treated as gospel by statesmen and military planners in the age of empire.

Mahan’s central insight was simple but powerful: command of the sea enables control of global trade, and trade underwrites national strength. From this followed a prescription for national strategy that still guides great powers today. He emphasised three pillars: naval strength, strategic maritime bases, and control of key sea lanes and chokepoints.

For Mahan, the nation that secured these three would possess outsized influence in world affairs.

The logic of sea power played out in the decades that followed. The British, German, American, and Japanese navies raced to build ever larger fleets, seeking dominance on the world’s most important trade routes. Naval arms races helped set the stage for the world wars, while postwar US naval supremacy shaped the global order for the better part of a century.

Mahan’s emphasis on “concentration of force” and the necessity of a forward-deployed fleet found practical expression in the vast US carrier battle groups that still patrol global waters today.

Yet Mahan’s work was never only about ships or battles. He understood that sea power rested equally on the ability to project economic influence, shape international commerce, and secure national prosperity. He warned that neglecting naval capacity or abandoning key maritime positions could spell decline, even for the mightiest nations.

The return of great power competition in the Indo-Pacific has given Mahan’s insights new urgency. China’s rapid expansion of its navy, construction of artificial islands in the South China Sea, and growing presence across the Indian Ocean fit precisely within the Mahanian logic of securing maritime dominance.

Chinese strategists openly cite Mahan as an intellectual guide, framing their quest for sea power as a necessary response to historic vulnerabilities. The Pentagon, for its part, has responded with a renewed focus on forward deployments and the defence of critical chokepoints.

Contemporary security alliances, such as the Quad and AUKUS, rest on Mahan’s vision that only coalitions able to sustain command of the sea can maintain order and protect global commerce. The Quad, which is a loose security dialogue comprising the United States, Japan, India, and Australia, aims to promote stability and deter coercion across the Indo-Pacific, while AUKUS, a trilateral pact between Australia, the United Kingdom, and the United States, is focused on sharing advanced technology and bolstering Australia’s naval power with nuclear-powered submarines.

From the Red Sea to the Strait of Malacca, the control of narrow passageways and key refuelling bases continues to decide the fate of shipping and trade. Recent disruptions, such as Houthi attacks in the Red Sea and piracy in the Gulf of Aden, have brought home the enduring relevance of these strategic calculations.

Mahan’s core lesson remains relevant today. The nation that commands the sea holds the keys to economic prosperity, political leverage, and long-term security. As the Indo-Pacific power struggle intensifies, his ghost still haunts the admiralties and war rooms of the world’s leading powers.

Those who ignore his teachings do so at their peril.

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