– UPDATE as of Feb. 3, 2021 at 4:55 p.m.

The USAOTC retirement ceremony honoring John W. Diem Friday, Feb. 4 at 2 p.m. has been cancelled.

Within minutes after posting this MEDIA ADVISORY, the Fort Hood Senior Commander closed Fort Hood on Feb. 4, 2022 due to forecasted freezing rain and sleet.

We apologize for any inconvenience.

Another update with a new link will be posted should the ceremony be re-scheduled.


WEST FORT HOOD, Texas – John W. Diem will retire in a virtual ceremony here Friday, Feb. 4 at 2 p.m. after serving as Executive Director of the U.S. Army Operational Test Command since November 2017.

The virtual link via Microsoft Teams is:

Mr. John W. Diem retirement ceremony via Teams

A resident of Bryan, Texas, Diem is the only senior executive service member at Fort Hood, and is the federal civilian equivalent to a one-star general officer.

He started his career service as an Army commissioned officer after receiving his commission as an Air Defense Artillery Officer from the University of Texas A & M in 1978. He became a test officer in January 1982 when he reported to his first duty station — Fort Hood — where he was assigned to TRADOC Combined Arms Test Activity as a military test officer in the Battlefield Automation Test Directorate known today as USAOTC’s Mission Command Test Directorate.

Since then, he has held positions of increasing responsibility in testing, training, and operations, to include service as the III Corps G3-Rear from 2003 to 2005 and as an innovator in the use of simulations to test and train combat systems, networks, and mission command in operationally realistic environments.

After his Civil Service retirement, Diem will be joining the staff at Texas A&M.

Diem’s biography can be found at:

Mr. John W. Diem biography link

He is being replaced by Harker Heights resident John W. Leffers as acting interim Executive Director.

Leffers entered Federal Service in September 2019 as the Senior Test Manager for USAOTC’s Maneuver Support and Sustainment Test Directorate. He hails from Utica, New York and retired after 28 years of service with the U.S. Army as an Infantry Colonel in 2019. He served three 12-month combat tours: Operation Iraqi Freedom (twice) in Iraq and Operation Enduring Freedom in Afghanistan.

Media wanting to cover Diem’s retirement event should use the Teams link above.

The USAOTC Public Affairs Officer can be reached at (254) 449-3686, or email: [email protected].