Complex sentence: His research into convoy operations during the Vietnam War, Iraqi Freedom and Enduring Freedom incorporated his firsthand experience riding convoys in Iraq and Afghanistan made him the leading authority on gun trucks and convoy security.
Split into simpler sentences: His research into convoy operations during Operation Iraqi Freedom and Operation Enduring Freedom incorporated his firsthand experience riding with convoys in Iraq and Afghanistan. This experience and his work on Vietnam War convoys, have made him the leading authority on gun trucks and convoy security.