A united India would probably have arrived on the world stage much sooner then India has today.
63 years of massive military expenditure by both Pakistan and India to stare each other down would never have occurred.
The horrors of partition in 1947, the wars of 1949, 1965.1971 and the clashes in The Rann Of Kutch, Siachin and Kargil would never have happened.
A look at the map will show you that from a purely geographical point of view, Pakistan, India and Bangladesh are fated to co-operated if they are to escape poverty and tackle the myriad of problems they face.
63 years is long enough to sort things out but to do that would have required a sincere and dedicated leadership. Pakistan lacks this and has fallen prey to one set of self-servers after another.
India has benefited from a relatively more stable post colonial set-up. While Pakistan's founder was dead with 18 months, India's lived 17 years after independence and was able to use his moral authority to impose stability.
While we hear about the problems besetting Pakistan, we should also acknowledge that India in spite of its impressive economic growth has a serious and very violent Marxist insurgency in 20 of its 28 states. the gap between rich and poor has not been bridged and the sense that the state has failed them is growing among a caste riven population.
The UK's fault? Surely every colonial power is to blame for the problems of a former colony. By definition, a master cannot allow a servant to rise too high in his abilities. The Empire encouraged Brits to come out from the UK to rule and discouraged natives from ruling themselves. If this had not been the policy, India would have thrown off Imperial rule decades before it did.
Jinnah, Nehru, Gandhi and Lord Mountbatten, all played a part in allowing the dynamics of partition to become Irresistable. Jinnah didn't want partition and neither did Gandhi but Nehru thought that it was in his interests to have it and then when, as predicted Pakistan fragmented within mouths of Independence, Nehru could have re-united India and delivered a political death blow to Jinnah.
Partition gave India almost all of the industries and resource needed for a modern state. pakistan was basically agricultural with little or no industry or resources. ALmost all the railway lines were in India and designed to feed India from territory that was Pakistani. Most of the harbours and airports were in India and to add insult to enjury, the parts of India that were to be ceded to Pakistan were whittled down to create the best advantage to India.
In the years from 1947, Pakistan has sunk mines, built Dams, factories, power stations and shipyards. The step motherly treatment hand out by the British regarding the distribution of national wealth and gold reserves is a factor. Only a Fast by Gandhi forced nehru to let Pakistan receive her share of military supplies from the former British Indian Army.
Mountbatten agreed with nehru but dispute countless predictions of Pakistan's demise, it still struggle on. Why? Because despite the pathetic leadership, hostility of neighbors and natural calamities, people are tough and resilient and patriotic.