when does the secretary of defense became president
United States Secretary of Defense The Secretary of Defense is sixth in the presidential line of succession, following the Secretary of the Treasury and preceding the Attorney General.[57]
United States Secretary of Homeland Security The current Secretary of Homeland Security is Kirstjen Nielsen following the appointment of the then-incumbent secretary, John F. Kelly, to the post of White House Chief of Staff by President Donald Trump.[6] It was announced on October 12, 2017, that Kirstjen Nielsen was nominated as Secretary of the Department of Homeland Security by President Donald Trump. She was confirmed by the Senate on December 5, 2017.[7]