Britain's Prime Minister Boris Johnson aboard Vanguard-class submarine HMS Vengeance during a visit to Faslane Naval base (HM Naval Base Clyde), north of Glasgow in Scotland on July 29, 2019. - New British Prime Minister Boris Johnson makes his first official visit to Scotland on Monday in an attempt to bolster the union in the face of warnings over a no-deal Brexit. (Photo by Jeff J Mitchell / POOL / AFP)