Nice to hear an articulate spokesman for the merits of soft power in the international arena who does not sound unduly naive or run away from hard questions. But Shashi Tharoor, who spoke about the emerging India at Hay today, is not just an historian and author. A professional diplomat, he was also India's candidate for UN secretary-general when Ban ki-Moon won. Tharoor came second.

That may be why David Miliband, in jeans and shirt sleeves, took the trouble to introduce his event and chair the Q&A; session which followed - against a background storm which Tharoor called "the Welsh monsoon". For a man supposedly plotting a leadership coup in London, he was actually giving his own quiet demonstration of soft power. The audience was impressed.

The foreign secretary was therefore on hand to hear an illustrative soft-power anecdote about India and Angkor Wat to which I will return. Tharoor's recurring theme was India's extraordinary diversity, potentially making her - as EP Thompson once mused - the most important model for the coming century.

But how? Tharoor dismisses the authoritarian Chinese blueprint - the choice between "bread and freedom" - as well as assorted fundamentalisms including nationalistic self-reliance of the kind that wasted the first 40 years of post-independence India - such a contrast to the booming, high-tech (8% annual growth) of today.

He also gently noted the limits of hard power - military coercion - from Vietnam. He did so in favour of secular, pluralistic democracy of the kind India exemplifies. If the US is a melting pot, then India is one of those trays served up in its restaurants - a series of separate compartments full of foods that are completely different but complimentary, the accomplished platform speaker tells his conference audiences.

The author of The Elephant, the Tiger and the Cellphone chose the phone to make his point about modern India. The founding fathers had noted how the East India Company arrived to trade and stayed to rule: beware of foreigners selling you things. So in 1947 bureaucrats, not businessmen, ran the economy in the name of self-reliance until the financial crisis of 1991 forced India to open up.

Now even communist ministers in Bengal say: Is globalisation bad for the poor? Can we resist it? That is not possible. "Even if it were it is not desirable." That debate is won. India is likely to enjoy the world's third largest economy - after the US and China - by 2030. It is all happening fast. India's youthful demographics give it yet another edge.

And the cellphone? From two million landlines between 600 million people, and an eight-year waiting list for an truly appalling service, India now sells eight million mobiles a month, more than even China or the US. Street vendors, coconut cutters atop their palms, taxi drivers, they all have mobiles - their own - on which they serve their customers.

"The cellphone has empowered the Indian underclass in ways that 45 years of talking about socialism failed to do," the international civil servant (born in London in 1956) reported.

Hardly surprising this analysis, from a highly educated, globalised member of the elite? No, and Tharoor periodically acknowledges all the grim statistics which represent most of life the still-impoverished 600 million rural masses.

Marxist insurgencies, hunger and illiteracy are also part of the new India, the fruit of a poverty which must be eradicated if the reach of India's soft power is to be extended through its many attractive faces - its TV soaps, so popular in Afghanistan, as well as its 100,000 rupee (£1,300) Tata cars.

And Angkor Wat? Twenty-five years ago, a Khmer Rouge minister told Tharoor that Indians had forgotten they are heirs to an Indic civilisation - "we are its last outpost" in Cambodia, he explained. By which he meant that the Khmer Rouge had resisted Vietnam's recent military conquest, conquest by a Chinese civilisation. Why had India supported Hanoi? The visitor asked.

Easy, replied the author. India's decision was political, to stop the Khmer slaughter, not cultural. But Angkor Wat is probably Hinduism's greatest temple - in Cambodia, not India - its religion exported there by peaceful traders, not on the end of bayonets: soft power in other words. Since India has been the home to Jews since the Babylonian exile, to Christians before Europe was, to 150 million Muslims to this day, it is an extraordinary crossroads: there is not a thought on earth which has not passed through an Indian mind. EP Thompson again.

Nice stuff and gracefully done. So much changed is the old stereotypes of Indians that a sweating European ran after our author at Schipol airport recently shouting: "You're an Indian, help me fix my laptop." From snake charmers to IT geeks in barely a generation.

Hard questions? From a Hay audience there were plenty: about women, pollution, GM crops (he favours them), rural unemployment, Kashmir and, of course, Burma. Gareth Evans, a former foreign minister of Australia, seated in the audience, asked about that one. Not much power, soft or hard, in dealing with Rangoon since the cyclone?

Tharoor agreed that untied relief aid without political muscle had been feeble. But he provided context. Twenty years ago, India provided help for the Burmese opposition and watched as China and Pakistan moved in on Burma - for oil and bases - while Rangoon established border camps for Indian rebel groups. Delhi's head overruled its heart.

What about Kashmir? Tharoor is an optimist. How could he not be? India wants peace, it does not want anything Pakistan has and has given its unreciprocated trading benefits. Relations between the two countries - and its people - are slowly improving.

But to allow a plebiscite now, one that India would have probably won in 1948, and let a Muslim majority in Indian-held Kashmir secede, would create all sorts of problems, not least for Kashmiris and for Indian Muslims.

Allowing citizens to secede on purely religious grounds would also undermine an India based on fundamental diversity in favour of Pakistan, a state whose very existence was rooted - at the time of partition in 1947 - on its Muslim identity.

A diplomat's answer, then, but a good one. India is the status quo power in divided Kashmir. Pakistan may be coming round to an accommodation which Indian soft power - a rising force around the world - may yet facilitate rather than threaten. Of course, Delhi also has the hard power option, too - which so alarms some geopolitical analysts. But Hay's optimist preferred to look on the bright side - despite the storm outside.