James Mattis (born September 1, 1950) is a retired United States Marine Corps general who served as the 26th United States Secretary of Defense from January 20, 2017, to January 1, 2019, under President Donald Trump. Mattis, often referred to by his nickname "Mad Dog Mattis," is known for his extensive military career, spanning over four decades, during which he held various high-ranking positions, including Supreme Allied Commander Transformation of NATO. In Hebrew, his name is translated as ג'ים מתיס, in Arabic as جيمس ماتيس, and in German as James Mattis. Mattis is highly regarded for his strategic prowess and has authored several publications on military and strategic affairs. His tenure as Secretary of Defense was marked by a focus on rebuilding U.S. military strength and countering global threats. Mattis retired from the military in 2013 after reaching the mandatory retirement age for generals and later joined the Trump administration in 2017. He resigned from his position in early 2019, citing policy differences with the president.