This is part of larger game.
1American need transit route to afganistan...its through pakistan.
2Pakistan supports people who america wants out...pakistan does not help them.
3 us wants to choke pakistan and wants them to stop ne support to haquannis n others...but directly cant coz this will starve their troops in afganistan.
4 iran us relatiins bad so direct acess dificult.
5 indian provides routes to america indirectly through chabhar.
Benefits to us
1 alternative route....easy to presurrise pakistan.
2 did not have to directly ask route from iran.
3 try to pull iran out of russia n china block via india.
Benefits to iran
1 trade n money.
2 a developing port.
3 indian involvment indirectly provides security to port n trade through it.
Benefits to india
1 acess to afganistan and central asia.
2 encirclment of pakistan.
3 more influence in afganistan.
4 economic warefare with pakistan...first trade is with wheat...balouchistan n kpk have large flour mills which are depended on afgan trade.
5 india can ask us for help against india centric groups in pakistan.
6 may be some naval assest near chabhar.
Benefits to afganistan
1 alternative trade route.
2 american forces will remain there
3 less dependency on pakistan
Benefits to pakistan
1 trying to figure out.
Loss for pakistan
1 economic n trade loss
2reduced influence on afgan
3 iran is nxt door nehbour with bettwr ties with india
4 americans more free to presurrise
5 loss of route to central asia via afganistan
6 uppeehand to india with iran n us n afgan support