Mattis has been sharply critical of President Barack Obama's policies on Iran and Obama's capping of troop numbers and campaign end-dates in theaters of war such as Afghanistan and Iraq. Mattis also appears to be a skeptic of the Obama-era policy of putting women into combat roles.

The senior director at the NSC for the Middle East is retired Col. Derek Harvey, an Arabic-speaking intelligence officer with a Ph.D. who served as the head of the U.S. military cell examining the insurgency in Iraq in 2003.

An intelligence officer and historian, Rayburn published a 2014 book, 'Iraq After America,' which is a must-read for anyone who wants to understand how Iraq descended into chaos in the years after the American troop withdrawal at the end of 2011.

The hard reality is that attacks by vehicles in public places are very hard to defend against in a free and open society. The best defense against such attacks is good intelligence, and that often comes from inside the Muslim community.

Social media companies must work closely with the U.S. government to ensure their platforms are not being used by terrorist organizations to do harm to our country.

There are many different artforms that are just being lost because the whole digital revolution has homogenized everything, turned it all into Walmart.

When it comes to social media, there are just times I turn off the world, you know. There are just some times you have to give yourself space to be quiet, which means you've got to set those phones down.

I think that new communications are wonderful and I am delighted to be a part of the Internet generation.