CSS versus ISSB : What do you want to do?

 If you want to join armed forces of Pakistan then you'll have to pass ISSB along with other tests. However if you want to serve as civil servant then go for CSS exams.

Comparing css officer with army officer, Well CSP officer right from the start have powers as CSP has to deal with public affairs mostly. So in public affairs matters CSP is powerfull. As for example ASP is more powerfull then Major of Army.

But after promotions of army officer to higher rank for example to Brig. OR Maj .Gen and so on. Powers of these ranked officers are aslo very much, as we all know we are enlslaved of our own army. Army is more powerfull then civil beurecracy.

But if you look in the perspective of direct powers then CSP has more powers than Army officals.

Army is indepennt organization while many CSP work under ministries. so politics can influence csp officer but not to an army offical.