BTW I also understand a Commissioned Officer's oath is one for life and can not legally be rescinded. In 1974 Ford recalled him back to active duty as Commander in Chief, United States European Command. The positions he held as a soldier he held active duty. The positions he held in government he was retired military not on active duty.
Alexander Haig retired as a four-star general from the Army in 1979, and moved on to civilian employment. In 1979, he became President, Chief Executive Officer (CEO), and Director of United Technologies, Inc., a job he retained until 1981. In January 1981, Haig was tapped by President Ronald Reagan to be Secretary of State.
I'd also add the following. Gen Haig received the following decorations from his service as a young combat infantry officer in Korea and in Vietnam as a Battalion commander;
Distinguished Service Cross
Defense Distinguished Service Medal with Oak Leaf Cluster
Silver Star with Oak Leaf Cluster
Distinguished Flying Cross with Oak Leaf Cluster
Bronze Star with "Valor device"
Air Medal
and most significantly, the Purple Heart