Understand
The area is inhabited by Pathans or Pushtuns, rather fierce Pushtu-speaking hill tribes. On the map, it is part of Pakistan, but the Pakistani government has never really controlled it. Pathan tribal chiefs run everything.
Pathan territory spans the border. 60% of them live in Pakistan, 40% in Afghanistan. In Afghanistan, they are the largest ethnic group at 40-odd% of the population and have often dominated government and business.
The Pathans have twice defeated the greatest armies of their day. When Alexander the Great wanted to cross the pass, he could not manage it for several weeks, until he bribed one of the local chieftains into assisting him against the ones who were blocking him. At the height of British power in Queen Victoria's reign, the Khyber was the border of the Raj. Britain fought several wars against Pathans and never completely subdued the area. In the first Afghan war, a force of 16,000 4500 soldiers plus grooms, cooks, etc. went in and one man came out alive. Pathans were also recruited into the British military, where they were excellent soldiers.
Since 1980, Pathans have been fighting Russians, various other Afghans, American and allied forces, the Pakistani army...and sometimes each other.
The Pathans provided most of the adherents of Taliban. Many — both pro and anti-Taliban — are still 2012 fiercely resisting various efforts by US and allied forces and/or the Pakistani government to control their area.
Crossing the Khyber has always been something of an adventure. Today, it is far too dangerous for most travellers.
