Prime minister hits back at US president over threat to leave Nato as he says how Britain emerges from Iran war crisis will ‘define us for a generation’ Sign up for the View from Westminster email for expert analysis straight to your inbox Get our free View from Westminster email Get our free View from Westminster email Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice Sir Keir Starmer has called for the UK to develop