Indeed Mullah Nazir was also believed to have formed a non-aggression pact with the Pakistani government and analysts say his death could be a contentious issue between Washington and Islamabad because the Pakistani military views commanders like him as key to keeping the peace internally.

BBC: Obituary: Mullah Nazir

He blames the so-called "pact of silence", which followed General Franco's death in 1975, in which an amnesty law, essentially forgiving Franco-era crimes, was approved as part of a precondition for a smooth transition to democracy.

BBC: Dig may lay Spanish poet mystery to rest