Martin Luther King Jr. ignited support across the globe, writes history scholar Stephen Tuck in an op-ed at the New York Times, and his legacy worldwide remains profound — and contested. Indeed, it was King’s “I have a dream” speech that sealed his global fame. We’ve all seen photos of the hundreds of thousands marching…

This week, British Prime Minister David Cameron has received the warmest of welcomes from President Barack Obama. Cameron became the first foreign leader to accompany President Obama on Air Force One, and — perhaps more important in the eyes of the president — the first foreign leader to accompany him to watch college basketball. In…