As the U.S. defense secretary under presidents John F. Kennedy and Lyndon B. Johnson, Robert McNamara was a central figure in the Vietnam War. While he confidently carried out orders, behind closed doors, he came to believe – very early on – that the war he was charged with leading was unwinnable.

The journalist and Stanford alum Philip Taubman ’70, who is now an affiliate at the Center for International Security and Cooperation (CISAC), examines the contradiction between McNamara’s public and private positions in his new book, McNamara at War: A New History (W. W. Norton, 2025). Taubman draws on previously unavailable material – including letters from Jacqueline Kennedy and a private diary kept by McNamara’s closest policy advisor – to gain a deeper understanding of McNamara and the complex legacy he left on U.S. and world history.

Here, Taubman talks about why McNamara’s story still serves as a valuable lesson for policymakers about what happens when loyalty and moral misgivings collide and the importance of democratic oversight of war.

Read the full Q&A at news.stanford.edu.