On October 10, President Donald Trump signed an executive order on the succession of the post of defense secretary, which lays out the order of succession the military should follow if the secretary dies, resigns or is otherwise unable to perform his or her duties. Trump’s move is particularly noteworthy at this particular moment in history.
General Mark Milley, chairman of the joint Chiefs of Staff, was noted not to be on the list.
The executive order indicates that in the event of the death, resignation or otherwise inability of the Minister of Defense, the Officials of the Ministry of Defense, in the order listed in the executive order, act on behalf of and perform the functions and duties of the Minister of Defense until the Minister of Defense is able to perform the functions and duties of the Minister of Defense.
The top order of the list is:
(I) Deputy Secretary of Defense
(ii) Secretaries of the Military Departments;)
(iii) Under Secretary of Defense for Policy;
(iv) Under Secretary of Defense for Intelligence and Security;
(v) Chief Management Officer of the Department of Defense;
There are many other lists (omitted)