United states is the powerful nation on earth. FULL STOP.
For the first 55 years of the sub continents independence USA was massively pro pakistani to the point of arming training the pakistani military. Even to the point of threatening india in 1971 to stop its invasion of the then East Pakistan by sending in their 7th Fleet carrier battle group.
USA in those days looked at india as a Russian client state. The indians where treated with mistrust but diplomatically very cool relations.
From the outside looking in throw china,s weight into the equation behind pakistan and you can see why Pakistan would feel the equal of india with those 2 giants flanking you.
TIMES HAVE CHANGED and pakistan can blame the fall of Russian threat and THE RISE OF CHINA to that..
USA is so worried by the rise of the dragon they are looking for new allies.
Pakistan is caught in the middle of CHINA OR USA sitution. Throw in you rise of islamic terror fear,, by the west thanks to 9/11 and you can see why USA/INDIA relations are warming up nicely.
India is already far stronger than pakistan be it diplomatically, military or economically. A PRO INDIA usa alliance will be difficult for pakistan to stomach
ONE FLANK WILL BE WIDE OPEN