Five former secretaries of defence are calling on Congress to hold immediate hearings on President Donald Trump's recent firings of the chairman of the Joint Chiefs of Staff and several other senior military leaders, according to a letter obtained by The Associated Press. The five men - who represented Republican and Democratic administrations over the past three decades - said the dismissals were alarming, raised troubling questions about the administration's desire to politicise the military" and removed legal constraints on the president's power. Late last week, Trump fired Air Force Gen. CQ Brown Jr as chairman of the Joint Chiefs. Defense Secretary Pete Hegseth followed that by firing Adm. Lisa Franchetti, chief of naval operations; Gen. Jim Slife, vice chief of the Air Force; and the judge advocates general for the military services. Hegseth has defended the firing of Brown, saying that other presidents made changes in military personnel and that Trump deserves to pick his own