The Porous Afghanistan-Pakistan Border

Various articles lately have mentioned the difficulty of patrolling the Afghanistan-Pakistan border, and the advantage the Taliban have in not needing to respect that border. I'd like to go one step further and illustrate just how impossible the border is to patrol. This image represents the elevations along the northern section of the border. Note the location of strategically important Khyber Pass. 

The border between Afghanistan and Pakistan, called the Durand Line after Sir Mortimer Durand, the foreign secretary of British India,  is merely the point where the British stopped conquering northward and allowed the harsh terrain and even harsher Pashtun tribesmen to serve as the border between them and Russian interests in Central Asia. 

This is some of the most rugged terrain on earth. Even with modern equpiment including helicopters it is virtually impossible to patrol. This, together with the determination of the tribal people who populate the region, is why we have not caught Osama bin Ladin, and why we will never be able to conquer this area by sheer force. Hard power is not an answer by itself; smart influence is needed.