A new festival has been added to the Indian ritual calendar. Like Dussehra and Diwali, it is a winter festival, but unlike them the gods it honours are living beings, who appear before us in flesh and blood instead of being frozen into stone. This relatively new addition to our lives is called NRI puja. It takes place in December, a time when thousands of Non-Resident Indians briefly become Resident Non-Indians.

Among visiting gods, Salman the creator, Amartya the preserver and Sir Vidia the destroyer are most prominent.

As a middle-class, English-speaking South Indian, I am always part of these festivities myself. For half my family serve as deities; the other half as worshippers. Whether I like it or not, I am placed by default in the second class. Fortunately, whatever personal apprehensions I have about participating in this annual puja are overcome by the force of professional obligation. As an Indian who chose to live in India, I might affect scorn for the migrants, but as a social scientist I must take cognisance of a phenonemon whose social significance grows with every passing year.

The first thing to note about this puja is that it has space only for a certain kind of NRI. Those who live with Arabs in the Gulf or with Fijians in the South Pacific do not qualify; still less those who have made their home with humans of African descent in the Caribbean. To be worthy of worship, an NRI must live with people whose skin pigmentation is, in the Tamil phrase, paal maadri, literally, the colour of milk.

Among the gods who visit us every winter, three deities tower above the others. Analagous to Brahma, Vishnu, and Siva, we have Salman the Creator, Amartya the Preserver, and Sir Vidia the Destroyer. Just as Brahma gave birth to the world, Rushdie gave birth, through his magnificent novel Midnight's Children, to an innovative and globally influential school of Indian writing in English. Like the god he resembles he appears to have done little since—but, for that first and fundamental act of creation, we worship him still.

Vishnu the Preserver is supposed to have had 10 avatars.

The radicalism of the Non-Resident Religious Radical and the Non-Resident political radical usually stems from deep alienation in a foreign culture.

His successor probably exceeds him in this regard. Sometimes he comes to us as a Bangladeshi (by virtue of the fact that he was born in Dhaka), at other times as a Bengali, at still other times as a Global Indian. Other roles he has assumed include economist, philosopher, sociologist, historian, and seer. Like the god he resembles he comes to cheer us, to console us, to chastise us.

Siva could set the world ablaze with a mere blink of the eyelids. His modern successor can destroy a reputation by a word or two said (or unsaid). As with Siva, we fear Sir Vidia, we propitiate him, and we worship him. Who knows, if we are diligent and devoted enough, he may grant us some favours in this world (or the next).

In the Hindu pantheon there are three main Gods as well as 33,000 lesser ones. Through the month of December, the Holy Trinity are sighted from afar—prayed to, occasionally touched, but rarely spoken to. But how many Indians get to go to Badrinath anyway? Their regular prayers are offered to more modest deities who live in or visit the smaller shrines in their own villages or towns.

Among these lesser gods, the first and by far the most numerous category consists of the Family Show-Off. This is the man—less often, the woman—who went early to the West, usually the United States, to study, work and earn. He makes trips home every few years—at first coming alone, then with Indian wife acquired through traditional channels, and finally with one or two brats in tow. When these family NRIs appear, we, mere permanent residents, are obliged to pay homage, altering our own lives and work schedules to do so. It is striking how naturally we slip into the role of worshippers; they, as naturally, into the role of the worshipped.

The Family Show-Off is more than willing to speak of the upward curve of his own life: of a better-paid job, a bigger car, a house on the coast. He is certain to note the very different conditions of your life—the traffic jams, the power cuts, the credit card machines that don't work, the water fit only for animals to drink. Some visiting NRIs express anger at these conditions. Others express sympathy, which yet comes with a very large dose of self-satisfaction.

Sometimes the Family Show-Off takes on a second role, that of the Non-Resident Religious Radical, or nrrr. The nrrr tells you that the only way to build a strong, self-reliant nation is to marry Faith with State. Like exiles everywhere, he yearns for the restoration of a pure, uncontaminated, national culture, which in his rendering can only mean a Hindu culture. These nrrrs have been to the Sangh parivar what North Americans Jews are to the Israeli Right and what Irish-Americans have been to the ira—that is, an important source of moral and (more crucially) material support.

When the BJP was in power, much attention was paid to the diasporic fundamentalist. But few, it seems, have noticed the steady growth in influence of another kind of diasporic extremist, whom I call the Non-Resident Political Radical, or NRPR. While the nrrrs tend to come from the commercial and professional classes—they are typically doctors, lawyers, and businessmen—the NRPR are located chiefly in the American academy, as students and professors. They are fervently against 'lpg': liberalisation, privatisation and globalisation. This, despite being beneficiaries of L, P, and G themselves. Some NRPR offer socialist Cuba as an alternate economic model; some others, the Gandhian ideal of the self-sufficient village economy. Where the nrrrs support a political party, namely the BJP, the NRPR are more prone to support, and influence, those social movements which share their distaste for the state, the market, the establishment; for, it seems, everything - and - everyone - but -themselves.

Both kinds of radicalism stem from a deep sense of alienation. The Hindu professional might live in suburban America but he shall never be of it. His neighbours can't pronounce his name, have never heard of his place of origin, don't warm to his music and are uncomprehending of his religion. Back home, however, there are people who both understand him and need him. So he writes cheques to the Vishwa Hindu Parishad, thus to preserve the essence of a culture too elevated for his narrow-minded neighbours to appreciate.

The university radical, for his part, also finds himself pyschologically out of place in America. His fellow dons all know their Marx, but in the wider society the ruling deity is Mammon. The only hope is to take succour in oppositional movements within India. When George Bush's America is so ferociously devoted to consumer capitalism, thank God for the desi leftists, who so heroically keep out the market and keep flickering the fading light of socialism. The Mother Country to the rescue, again.

Both kinds of radicals are hypocritical. Living under a Constitution that separates Church from State, the religious radical yet wishes to convert India into a Hindu Pakistan. Living in an open, free society that encourages innovation and enterprise, the political radical yet wants to refashion India into a Burma writ large, into an isolated, autarkic autocracy that shall pass itself off as a socialist utopia.

To be fair, and for the sake of completeness, I must note that there are many Anglo-American NRIs who do not fall into the categories identified above. These are human beings and not deities, as unsure as normally resident Indians normally are about how to improve the country or settle the fate of the world. With these ordinary NRIs our relationship is rather more equitable—for they talk to us, rather than down at us.

When was the first ever NRI puja held? I think I can say without too much fear of contradiction that it was not before the 1960s—when the first big wave of professional emigration into the US began—that this particular festival entered our ritual calendar. At first it was observed in isolated pockets, chiefly in south India. But over the years the number of deities grew and grew. Besides, they now came from every state of the Union, returning each winter to show their face and receive devotions in return.

However, it is just conceivable that the festival has peaked, that its most glorious days are behind it. With the surge in the economy, the previously disadvantaged worshipper has disposable cash of his own; now, come late December, he seeks to holiday in Bali or New Zealand rather than stay back for the rituals at home. In any case, repeated contact with the deity has led to a certain disenchantment. Some of us cannot wait now for the New Year to ring in and the flights to New York to take off, so that we can turn, with relief and anticipation, to worshipping those Gods—Shahrukh Khan and Sachin Tendulkar pre-eminent among them—who come not on fleeting annual visits but are with us (and in us, and for us) always.