In his letter to Zarb-i-Momin, the Taliban publication, Mr Azam Tariq, leader of Pakistan's violently sectarian Sipah-i-Sahaba Party, is ecstatic over his ideological brothers' recent victories. His ecstasy is shared by Pakistan's national security managers, but for non-ideological reasons. The attainment of "strategic depth" has been a prime objective of Pakistan's Afghan policy since the days of General Ziaul Haq. In recent years the Taliban replaced Gulbadin...