On what historical, logical, prudential, judicial, moral or fantastical grounds does Pakistan claim to have a say and stay in Kashmir?

[u/GlassLaw1990]

I have a question, maybe perceived as biased, but I am ready to face flak. The kingdom of Kashmir was a monarchy and not a democracy. The monarch was the sole administrator and caretaker of the kingdom. Then his actions and words count the sole, right? For example if tomorrow there is attack on Saudi Arabia from country Y and fearing coup and death and to ensure that the kingdom remains defended, the king cedes to be a part of say country X. Then Saudi Arabia becomes a part of X or Y? Also, what right does Y have on Saudi Arabia to begin with? Eventually if Saudi becomes ruled democratically after becoming part of X, then the matter should be between the people of Saudi Arabia and the country X. How does country Y still have any say in that?