That entire narrative is based off the bullshyt assumption that one man can choose the fate of an entire people. Especially bullshyt in an age when the British were literally picking who the king of Jammu & Kashmir would be.
I'm not justifying Pakistan's actions but the constant reliance on what this one single British pawn signed has always seemed weak as fukk to me.
What did the people vote for? What did the legislature vote for?
I feel that but it is much more legitimate than Goa, Hyderabad, and Arunachal Pradesh. Those were straight-up conquests. Nehru sent in the army and took Goa by force from Portugal, he took Hyderabad by force from the sultan, and he took Arunachal Pradesh by force from China.
Those situations are entirely comparable to Ukraine because they were invasions of foreign territory, although culturally Indic (just as Ukraine and Russia are both culturally Slavic), and although historically closely linked (just as Ukraine and Russia were once part of the same nation), they were nevertheless invasions of independent foreign territory.
I insist that Jammu & Kashmir was not because even if you argue that the king's signature does not give the people's consent, at the end of the day none of it would have happened if Afghanistan and Pakistan hadn't invaded his kingdom. He was under attack and he needed someone to defend the land. It's not like the Ukraine situation at all. If Ukraine had zero military and asked to join Poland to gain a military for defending itself, then you could compare the issue to the Kashmir dispute.
Pakistan is clearly the aggressor and the whole reason there is a dispute is all their fault. They are to blame. In this story, they are the Russians. If Poland doesn't want to give Ukraine up, well that's not morally ideal, but it's still better than being Russia.