Pakistan would only give tough time on ground offensive but eventually the options would reduce maybe as a last resort use tactical nukes on its own land against an enemy that has come from far off, in Air Battle or Naval Battle Pakistan would lose outright against US/NATO. Lets not fool ourselves into and should only discuss whom we can really challenge not US/not NATO.
Please do good research before penning down like that; Pakistan Army has lost soldiers/officers unfortunately like ants to those terrorists in huge numbers in my opinion we are missing some plans which needs to be revisited, we can't even establish proper concrete protected Posts against taliban attacks, A large sophisticated over whelming enemy has always plans see the wider picture WWII Germany vs Allied Forces. The only smart way is to make friends Internationally and cooperate but on equal terms for that Pakistan needs to be strong economically.