LTG Hertling served a total of 38 months in combat – as a major in a cavalry squadron during Desert Storm, as an Assistant Division Commander in the 1st Armored Division in Baghdad in 2003-4, and as the Commander of 1st Armored Division and Multinational Task Force Iron in Northern Iraq in 2007-8. His other commands include the Army’s Initial Military Training Command (Basic Training), the Army’s National Training Center in California, the Joint Multinational Training Center in Europe, an Armored Brigade Combat Team focused on reinforcing the Korean Peninsula, and the Army’s first Stryker Brigade. Hertling was the Joint Staff War Planner (J7) during 9/11 and after.

After retiring from the Army, LTG Hertling became a Senior Vice President for a major healthcare organization in Orlando, retiring from that organization in 2018.  He was appointed to the President’s Council on Fitness, Sport and Nutrition by President in 2014, and in 2021 he was appointed by President Biden to be a commissioner of the American Battle Monuments Commission, where he now serves as Chairman.  Mark was an adjunct scholar at West Point’s Modern War Institute from 2014-2020, and he actively teaches as an adjunct professor of strategic leadership at the Crummer School of Business at Rollins College.  He also serves as an executive member of the Dean's Alliance at Indiana University’s School of Public Health.  Since 2013, Hertling has provided military and national security analysis for CNN/CNN International.

Hertling is a graduate of the US Military Academy at West Point, holds 3 Master’s Degrees and a Doctorate Degree, and his awards and decorations include three Distinguished Service Medals, six Bronze Stars, the Army Commendation Medal for Valor, the Purple Heart, the Combat Action Badge, the Parachutist Badge, and awards from the governments of Romania, Poland, Germany, Saudi Arabia, and Kuwait.

Mark is married to his best friend, Sue, and they moved to Flagler Beach in January 2021. They have two sons, and five grandsons.