The US government is on a ‘burning platform’ of unsustainable policies and practices with fiscal deficits, chronic healthcare underfunding, immigration and overseas military commitments threatening a crisis if action is not taken soon, the country’s top government inspector has warned. David Walker, comptroller general of the US, issued the unusually downbeat assessment of his country’s future in a report that lays out what he called “chilling long-term simulations”. These include “dramatic” tax rises, slashed government services and the large-scale dumping by foreign governments of holdings of US debt.