Admire Barack Obama's endurance on January 26th, when he becomes the first American president to be guest of honour at India's annual Republic Day parade in Delhi.

For two long hours he will inhale the capital's smog as he and India's prime minister, Narendra Modi, review a procession of military hardware, trick-motorcycle riders and troupes of dancers.

A chilly winter morning on Rajpath, New Delhi's main ceremonial boulevard, can be an eternity.

Mr Obama is coming to India on a three-day trip to improve an already strong bond with the country's barrel-chested leader.

He will become the only sitting American president to visit India twice, and he arrives barely four months after Mr Modi went to Washington. The two men also got together on the sidelines of an Asian summit in Myanmar in November.

So frequent are their encounters that underlings hardly have time to prepare substantial matters to discuss. (Speculation this time centres on a possible deal to lessen the potential liability American firms face if they invest in the nuclear-power industry — Indian law holds contractors liable for all costs.)

Yet mere symbolism can be useful. Indeed, it may help banish memories of an awkward clash between the two countries last year, after police in New York clumsily arrested an Indian diplomat over the immigration status of her Indian maid.

That incident aside, bilateral relations have steadily improved over the past 15 years, often against the opposition from older Indian diplomats who cling to a belief in non-alignment — isolationism mixed with leftist moralising. Younger ones, however, grasp what there is to gain by engaging with a country with so much capital, technology and trade potential to offer. Most Indians view America positively.

Mr Modi's recent predecessors forged closer American relations. But they were wary both of China and of their own stuffy bureaucrats, and were shy of making a tilt to the West too explicit. The difference now, according to Tanvi Madan of the Brookings Institution, a think-tank in Washington, is that under Mr Modi India is at last taking America "home to meet Mum".

Ms Madan emphasises the importance of the Indian diaspora in America (over 3m Indian-Americans, many of them rich, educated and influential in government, politics and business) and of tapping America to strengthen India's economy and military capacity.

Today India and America co-operate on intelligence (especially since terrorist attacks in Mumbai in 2008 killed 166, among them six Americans).

The two share a certain mistrust of Pakistan, formerly a close American ally, and are alarmed at Islamist extremism there.

Where India, the world's biggest arms importer, once turned to Russia as its traditional supplier of defence equipment, it now increasingly favours higher-tech gear offered by America, Israel and others.

In November Russia sent its defence minister to Islamabad, Pakistan's capital, for the first time in over two decades, signalling that it might begin arms sales to Pakistan.

So expect further Indian diversification. Mr Modi's hope is to have some American defence equipment made in India. But given that India caps foreign ownership of local defence firms at 49%, it is unclear how realistic that hope is.

Beyond defence, the two leaders share the idea of promoting India as capable, one day, of taking on bigger foreign roles. Rudra Chaudhuri, author of a recent book on how the two countries get on, sees "a serious shift" under Mr Modi in terms of a more active role for India abroad, beginning in its region.

Indian strength would inevitably rest, first, on its economy expanding faster. That notion was boosted this week by the IMF, which forecast that India's pace of growth will outstrip China's in 2016 (China remains much the larger economy).

Mr Chaudhuri points also to Mr Modi's personal rapport with other Asian leaders, notably Shinzo Abe and Tony Abbott, respectively prime ministers of Japan and Australia. Both countries are close allies of America. Mr Abe was last year's guest at the Republic Day parade.

Now Mr Modi shows a keen desire to raise India's profile further, at a time when America is pushing for more co-operation among Asian democracies, partly in response to a more assertive China. Myanmar aside, Mr Modi has travelled abroad only to visit democratic countries since he became prime minister last year, and talks up democracy.

Instructive, too, is that relations are likely to flourish with Sri Lanka, ending years of strain, after voters there replaced an authoritarian government — with Indian spies lending a hand, according to reports. Even if that detail turns out not to be true, Indian diplomacy looks more active than for a long time. Not a bad moment for Mr Obama to drop in for a parade.

Click here to subscribe to The Economist