India is already an important military power. It has the world's second-largest army, with more than 1 million well-trained men and 4,000 tanks, the fourth-largest air force and nuclear missiles capable of reaching targets as far away as Beijing. But the institution most crucial to its global future, and its links with America, is its navy. Indian politicians have been raised on British ideas about the importance of sea power. In the words of India's first premier, Jawaharlal Nehru: "To be secure on land, we must be supreme at sea." The Indian navy, or IN, sees itself as the direct heir to the Royal Navy's hegemony in the Indian Ocean, which was once the equivalent of a British lake - and now seems likely to become an Indian one.

India's fast-driving economy, which is expected to grow at an annual rate of 8 per cent in coming years, means there is plenty of money available for military expansion. The IN is no exception, with Indian naval spending having tripled since 2004.

But the key to the IN's future is its plans for projecting power in the skies. By 2011, India will have two full carrier battle groups in service, and IN Chief of Staff Admiral Madhvendra Singh has said he wants a third. More joint exercises with the US navy can be expected in the future, as the IN carrier groups seek to establish a Pax Indica across the region.

Americans need to remember that India will soon have the power to tip the strategic balance in three regions vital to US interests. The first is East Asia, where China's growing military might worries the Indians as much as it does the Americans. Not only do they confront China along a 2,000-mile land border, but China's strategy for a forward naval presence in places like Burma and Indonesia represents a direct challenge to India's ambition for ruling the waves in the future. As a partner of the US, India's carrier groups and submarines would be an important counterbalance to Chinese ambitions, especially towards Taiwan, and make a valuable fit with American forces in the event of war.

Then there is the Indian Ocean itself, a vital arena for world trade and oil shipments. Close to half of the world's overseas commerce passes through the Indian Ocean, as well as a fifth of the world's oil and gas - including supplies for China and Japan, as well as India. US Defence Department analysts have predicted that when China and India reach South Korea's level of per capita energy use, their demand for fossil fuels will total 120 million barrels a day. That compares with today's world daily demand of 79 million barrels. Hence, India's desire to protect its ties with oil-rich Iran; and its worry about finding new sources of energy, including nuclear power. With almost 65 per cent of India's oil needs coming out of the Persian Gulf, and 3.5 million Indians working in Gulf countries, it is unlikely that the new India will see its interests halting at the entrance to the Straits of Hormuz. That, in turn, makes working together with the US to stabilise the Middle East a crucial part of the IN's role in protecting India's security.

That overlaps with another priority in the war on terror: preventing terrorist piracy, one of the latest and most dangerous options for al-Qaeda terrorists. "The hijackers of today," says retired IN Admiral PS Das, "are hard-core terrorists." Groups like the International Maritime Bureau continue to monitor an alarming rise in terrorist piracy threats in Southeast Asia, as al-Qaeda and its offshoots eye points that could choke global trade, such as the Strait of Malacca and Strait of Singapore - both vital to India's access to Asian markets. Indian security officials well remember that the explosives used in the 1993 Bombay terrorist bombing were brought in by sea. They have a crucial interest in preventing the kind of spectacular 9/11-style attack - such as blowing up a hijacked tanker - that would plunge Asian financial markets into turmoil. Here the US and Indian navies' shared interest in keeping the world's trading lanes free of pirates and terrorists.

Even apart from strategic interests, the logic of history dictates a strong partnership between the US and India, just as it did with Britain in the previous century. A shared English-speaking heritage and a shared tradition of constitutional government and law give India a stronger cultural tie to America than any other Asian country - and vice versa. Just as Britain became America's intermediary with continental Europe, so India can be a powerful intermediary in dealing with powers like China, Russia and Iran.

This opportunity must not be allowed to slip away. As the clouds gather over America's relations with China, and the US strategic burden grows in the Middle East, a strong Asian ally like India becomes imperative. A century ago, America found its destiny by forging a partnership with the British lion; tomorrow, the same can - and should - happen with the Indian elephant.

Arthur Herman

Special to The Nation

Arthur Herman's most recent book is "To Rule the Waves: How the British Navy Shaped the Modern World" (Harper Collins/Perennial, 2005). He is currently working on a book on Mahatma Gandhi and Winston Churchill.