I think it is impossible to stop the violence without the formation of the Pashtun state, which includes part of the territory of Pakistan and Afghanistan. But Pakistan is not likely to agree with this.
It would also be, another landlocked state and if history is any marker, they will be countless infighting and tribal warfare on a greater scale.
Neither would Afghanistan want to merge with them, they dont want another 35 million Pashtuns to disrupt their fragile social dynamics.
In the end of the day, despite all the politics, Pakistan and Afghanistan are brothers, our history has always been intertwined and the two countries are realizing that they need each other more and more despite whats often reported in the media.
Furthermore the majority of Pashtuns live in Pakistan, and are interlinked with the historic Indus river region that courses down its heart. Karachi hosts a Pashtun population of 6 million making it the largest population of Pashtuns in the world. Lahore has 1+ milliion. What would make more sense is that the Pashtun majority areas of Afghanistan merge into Pakistan or that Afghanistan as a whole join with Pakistan in a confederation(as it was as recently as the 18th century) but with a democratic parliamentary system if you really wanted to talk about regional stability. The idea again has been in the pipelines since 1950's under Zahir Shah and Liaquat Ali Khan.
(found this interesting video on youtube)
Incidently, The founder of Afghanistan (Ahmed Shah Abdali) was born in Multan, Pakistan.
Going back to the point of this forum, the northern route is unfeasible and every military planner and strategist is fully aware of this fact. Let alone the financial costs (which would increase to unimaginable levels), the logistics of travelling through so many countries and opening up of another front is futile. Even best estimates suggest this route wouldnt be able to handle the volume or even come close to that which is occuring through Pakistan currently.
Another point to ponder, Nato/US getting supplies via Russia? not thats its impossible, but im sure thats going to raise questions. besides the US army has longstanding ties and a strong relationship to Pakistan and its armed forces.
Without Pakistan's support, the whole operation in Afghanistan will fail. Thats a fact. They need Pakistan more than Pakistan needs them despite all the fanfair to the contrary.
Pakistan did not have suicide bombings and terror at this level prior to the US/Nato mission in Afghanistan. Pakistan is doing more than any other nation in this war and needs to be appreciated a lot more because of the sacrifices she and her people have made. It lost the most both in civilian casualties, troop deaths, and economically has suffered despite the petty aid it is receiving. Much of its infrastructure(roads, schools, rail link) have suffered.
Its because of Pakistan's logistal assistance that US/Nato troops are able to eat, fight and be supplied at any given time in landlocked Afghanistan. They can play this northern route card all they want, quite frankly, many Pakistani's would be quite happy if they stopped using our logistical routes, but lets get real here, there is no military operation in Afghanistan without Pakistan's backing and support...period