The British had no choice but to "allow" it. It's like saying "the only reason india exists is because British 'allowed' it"
After WW2, British were done and dusted, they had to leave their colonies and the world was moving past Western hegemony. At that point,
Hindus tried their hardest to keep their remaining ancient homeland entact
but Muslims FORCED the division of indian territority
into three.
There is no two way around it because it is a recorded fact of history. Congress and Nehru was adamantly against the division. Hindus as a whole rioted against Muslims too----yet, Hindustan was
divided and you lost a huge chunk of territory.
Two-thirds?
More like half or a bit more than half. Furthermore, Kashmir was supposed to be fully with india when Hindu raja "gave" it to you.
We invaded and took almost half the Kashmir, and conquered the most strategic lands of it----completely cutting off india from Central Asia (one of the most resourceful and strategic area of the world). All you have is useless valley with no strategic value. And please don't come back with idiotic statements like "but we control water"....You don't. Indus will flow downstream no matter what. You can not alter one of the largest rivers of the world. Yes, store more water out of it---sure. But Indus was and will remain a Pakistani river. Secondly, Indus and other rivers don't even originate in india but China
And if indians try to mess with it, our allies will just do the same from their end and it will all be back to zero.
You are 1.3 billion, in what imaginary world you think anyone EVER expected that you won't get the "bigger territory" out of the division? The idea isn't that you have bigger territory---the fact is that you were supposed to have MUCH BIGGER territory since it belong to hindus for thousands of years----and Muslims just decimated hindu presence from
vast lands, ruled the remaining hindu lands for centuries, and
after all of that, still divided the remaining hindustan
into three
Read the British road-map for division papers that all the parties agreed to when Muslims won their case of division.
The "contiguous" Muslim-majority regions in North-Western India were to be made a separate state, and Punjab and Bengal were to be divided. Princely states were to decided between India and Pakistan.
So the idea that Pakistan were to have Hyderbad or UP under our control is nothing but a figment of your imagination to hide the embarrassment and humiliated Muslims gave to your country and peoples by dividing it after ruling it for centuries
Jinnah objected to some thinly Muslim-majority districts being given to Sikhs in Punjab. That's all. Nobody EVER claimed that Jinnah expected UP and Hyderabad to be in Pakistan
And on the case of the territory, Muslims got MUCH BIGGER territory proportionally. Today, your population is 7-8 times bigger than us, but your territory is only 3.7x bigger 
Poor hindus got r@ped, conquered, and destroyed by Muslims, their indic civilization completely engulfed by Isalm in Afghanistan, Indonesia, Malaysia etc, and then also lost their remaining lands to division because of Muslims. Infact, hindus lost some of their most sacred and ancient lands of Sindhu to Muslims. I understand why there's such hatred in your hearts regarding us. Awww, so shorrryyyy
