US President Donald Trump fired the chairman of the Joint Chiefs of Staff, Air Force General C.Q. Brown, and pushed out five other admirals and generals in an unprecedented shake-up of US military leadership. Trump said he would nominate former Lieutenant General Dan 'Razin' Caine to succeed Brown, breaking with tradition by pulling someone out of retirement for the first time to become the top military officer. The president will also replace the head of the US Navy, a position held by Admiral Lisa Franchetti, the first woman to lead a military service, as well as the air force vice chief of staff, the Pentagon said. Trump's decision sets off a period of upheaval at the Pentagon, which was already bracing for mass firings of civilian staff, a dramatic overhaul of its budget and a shift in military deployments under Trump's new America First foreign policy.