When it came to the Vietnam War, Mr. McNamara was an early advocate of escalation but came to realize the flaws in the American approach earlier than many of his colleagues. Yet in public, he continued to defend the war.

We know that often holding those who have carried out mass atrocities accountable is at times our best tool to prevent future atrocities.

Since 9/11, there has been a huge leap in people wanting to get personally involved in public service and international affairs.

India is at the vanguard of figuring out how to exploit technology and innovation on behalf of democratic accountability.

When it came to the Vietnam War, Mr. McNamara was an early advocate of escalation but came to realize the flaws in the American approach earlier than many of his colleagues. Yet in public, he continued to defend the war.

Democracies are expense-averse and they think in terms of short-term, political interests rather than a long-term interest in stability.

I was interning in the CBS sports affiliate in Atlanta with Robin Roberts.... I was taking notes on a Braves-Padres game, and on the live feed came footage of these kids protesting and getting crushed during the Tiananmen Square uprising in China in 1989. In that moment I became like a lot of young people in this country today, horrified and inspired but confused as to what I might do.