Michael Mullen

I was in the military for over 40 years, and one of the principles I kept with me was that there's an expectation globally that the U.S. will lead. Questions about that expectation have certainly risen in recent years. The fact that there's even a question about that is worrisome to me, and I think needs to be for a lot of people.

The price of diamonds can vary greatly depending on size, cut, color, and other factors, including whether they have a history. But because of the rarity of blue boron diamonds, they often fetch more money than gems of similar quality.