The resignations of defence secretary John Healey and armed forces minister Al Carns have thrown the prime minister into a fresh political crisis at home – but even worse, writes Francis Tusa , Starmer’s failure to keep his promises to Nato makes the UK look feeble in the eyes of its closest allies I was at a defence conference, having had the keynote from the chief of the defence staff, Air Chief Marshal Sir Rich Knighton, when the news broke that the defence secretary, John Healey, had