During the Persian Gulf War, he served as the Operations Officer (S3) of the 2nd Battalion, 3rd Field Artillery in the 3rd Armored Division at the Battle of Wadi Al Batin.
Erickson retired in October 1997 to teach world history at Norwich High School, but was recalled to active duty in March 2003 for Operation Iraqi Freedom and was assigned as the Political Advisor to Major General Ray Odierno, 4th Infantry Division.
Erickson retired as a full professor of military history after teaching for eight years in the War Studies Department at the Command and Staff College, Marine Corps University in Quantico, Virginia from 2009 to 2017 and is now an independent scholar.
[7] Erickson responded two years later in a letter to the Journal of Political and Military Sociology, explaining the delay as due to being in Iraq and labeling Dadrian's allegations as "deliberate obfuscations, misquotes, and slanderous comments."
Hovannisian also criticizes the book for factual accuracy, stating "The questionable or spurious assertions made in Ottomans and Armenians are far too numerous to list in their entirety.