The United Nations has warned up to half a million Afghans could flee the country by the end of the year – appealing to neighbouring countries to keep their borders open.
But Pakistan has already built a border wall, turning crowded crossings into scenes of desperation.
In the last few hours there have been firefights across the frontier.
For those attempting the long journey to western Europe – many will have to cross through Turkey.
A path well-trodden lined with obstacles.