Safeguarding NATO supply lines

As you have probably heard, NATO fuel supplies have been attacked in Pakistan:

http://www.bbc.co.uk/news/world-south-asia-11463490

Supplies going through the Khyber pass have also been stopped by Pakistan. How great a threat does this pose to NATO operations in Afghanistan? With up to 80% of NATO’s ‘non lethal’ supplies traveling by road through Pakistan, how can these be protected, and what alternatives are on offer if they cannot be?

This supply line could well prove to be NATO’s weak link, yet nothing seems to be done about it :confused: