WASHINGTON - A US government watchdog said Tuesday the Pentagon has barred it from disclosing how much of Afghanistan is under Taliban control - a significant break from past accountability that comes amid mounting security woes in the war-torn nation. At issue are the number of Afghan districts, and the populations living in them, considered to be held or influenced by the Kabul government by insurgents or contested by both. The US government has sometimes referred to such numbers in the 16-year-old war to show how the Afghan security forces are faring against a resurgent Taliban.