John Healey resigned as UK defense secretary after criticizing the government for failing to provide adequate military funding.The departure of Healey, alongside armed forces minister Al Carns, leaves Prime Minister Keir Starmer facing a significant political crisis.Internal disputes regarding the Defense Investment Plan have surfaced ahead of a critical NATO summit, highlighting a deep divide over national security budgets.Current military readiness has suffered under existing constraints, with all five nuclear-powered attack submarines currently undergoing maintenance or repairs.