As a protégé of Johnson, Matthews was similarly perceived as a liability in a now radically changed budgetary and national defense environment. Under political pressure from the Truman administration, Matthews also resigned as Secretary of the Navy in July 1951 to become Ambassador to Ireland, the home of his ancestors. Matthews was replaced as SECNAV by Dan A. Kimball, who had been Assistant Secretary of the Navy for Air under SECNAV Sullivan and who had been elevated to Under Secretary of the Navy following Sullivan's resignation and Matthews' appointment.