What's behind Pakistan-Afghanistan conflict?

Pakistan bombed major cities in Afghanistan including the capital Kabul on Friday, with Islamabad's defence minister declaring the neighbours at "open war". It comes after months of tit-for-tat clashes, with Islamabad accusing Afghanistan of failing to act against militant groups that carry out attacks in Pakistan, which the Taliban government denies. France 24’s Douglas Herbert takes a closer look at the causes of the conflict.

By FRANCE24