U.K. Defense Secretary John Healey has resigned, saying the government is not willing to spend enough on the military at a time of rising threats. Healey told Prime Minister Keir Starmer on Thursday that the government's defense investment plan falls "well short of what is required at this dangerous time." Publication of the plan has been delayed amid reports of disagreement between the defense ministry and the Treasury. Healey wrote in a letter to Starmer that "I am now left with no other option to submit my resignation." Analysts said the departure both undermines Starmer and sends a worrying message about the UK's ability to defend itself.