Separated at birth in 1947, India and Pakistan have since fought three wars as well as an armed, but localised, conflict in the Kashmir mountains, while India has been subjected to several terrorist attacks carried out by Pakistani citizens, most notably in Mumbai in November 2008.
In what can only be described as a charm offensive couched in the terribly obfuscating jargon that only economists and bureaucrats pretend to enjoy, India's Commerce and Industries Minister Anand Sharma crossed the Wagah border by foot this month and entered Pakistan. He was accompanied by a 150-member delegation of high-powered businessmen, cynical journalists - and eight chefs from the noted Taj group of hotels.
Crossing the India-Pakistan border at Wagah, as opposed to taking the 45-minute flight between Delhi and Lahore, is like retracing the journey that millions of Indians and Pakistanis took when the country was partitioned in 1947. Today this is a no-man's-land, fenced with several layers of concertina wire. In 1947, it was the site of many massacres.
Mr Sharma had hoped that he could at least partially erase the long history of mistrust by offering trade incentives to Pakistan, as well as lifting the ban on Pakistani investment in India.
In both Lahore and Karachi, the Indian delegation was overwhelmed by the positive response of the business community.
But in Islamabad, the country's capital, Prime Minister Yousaf Raza Gilani's coalition cabinet refused to give approval to a note that laid down the process of giving Most Favoured Nation status to India.
It was a reversal, after the cabinet's announcement in November that it would award the special trade status.
The distance between the governing and the governed, in this case between Pakistan's political classes and the business community, could not be bridged.
Mr Sharma had naturally hoped he would return home a conquering hero, beaming with pride as he told India's Prime Minister Manmohan Singh that he had paved the way for normality with Pakistan.
Imagine if the daydream had come true. Imagine the attendant benefits, ranging from a freer visa regime that would enable ordinary citizens to reunite divided families across the border, to an integration of the electricity grid - at least between the two provinces of Punjab in each country - as well as to the building of pipelines that could carry India's excess of refining production into Pakistan.
With the people of India and Pakistan fundamentally re-evaluating their relationship, both in practice and as it is perceived, what place would there be for terrorism in the future?
Now, even if daydreams have a habit of coming undone, as we saw the morning after Mr Sharma's trip to Pakistan, that does not mean that the Indian establishment should lapse into sullenness.
New Delhi should exhort its officers in the commerce ministry to come up with new ideas for their counterparts in Pakistan that are so tempting that Islamabad will not be able to turn them down.
Of course, Pakistan must allow itself to emerge from its sea of insecurity about its eastern neighbour and take a leaf from the people of its diaspora across the world. It's a truism that elsewhere, Indians and Pakistanis, irrespective of religion, caste and creed, somehow rediscover each other and form worthwhile relationships.
Perhaps the Pakistani government, however besieged it finds itself today, could turn one eye to the future and ask itself how India - a rising economic power towards which the rest of the world is gravitating - can also help Pakistan.
New Delhi has no choice but to adopt a Sisyphean ethic. If the boulder rolls down the hill, India must put its shoulder to the rock and roll it back up again. That's the nature of things when you want to become a regional power.
Taking responsibility for some of Pakistan's - and indeed, South Asia's - problems means that India must take a deep breath, and offer a larger vision of the world, or at least of South Asia.
In such a place, the partition of India in 1947, and the second partition in 1971 when Pakistan was subdivided with the birth of Bangladesh, would remain sacrosanct.
But if goods began to move across Punjab's Wagah as well as through check posts between the two Kashmirs, in ever-increasing quantities, then the rigidity of the frontier would give way to a softer border.
After 65 years, it is time to look at the India-Pakistan relationship with new eyes. And it is time to give trade a chance to improve things.
Jyoti Malhotra is a political and foreign affairs analyst based in Delhi