Well its quite a gamble.At there part of land i.e Afghanistan,they have already initiated dialogues with talibans which is a clear indication of the fact that this war cannot be won through military solutions only.Further if Pakistan accede to their request of joint action, what is the guarantee that they would clean up the affected tribal territory with in one year,the goal they failed to achieve in afghanistan in so many years, as it is already declared by President Obama that American forces will evacuate Afghanistan by july 2011. in short this kind of action will only further add to the troubles of Pakistan and nothing more.