Donald Kagan (/ˈkeɪɡən/; May 1, 1932 – August 6, 2021) was a Lithuanian-born American historian and classicist at Yale University specializing in ancient Greece.

[1] He attended Thomas Jefferson High School, where he played football,[1] before becoming the first person in his family to go to college.

[2][3] Donald Kagan's political views underwent a significant shift around 1969, moving from liberalism towards neoconservatism.

Kagan felt the university administration's response was inadequate, deeply impacting his political outlook.

He became one of the original signatories of the 1997 Statement of Principles by the neoconservative think tank Project for the New American Century, co-founded by his son Robert.

[4][5] In the lead-up to the 2000 presidential elections, Kagan and his other son, Frederick, published While America Sleeps, advocating for increased defense spending.