I would consider the principal threats to start with Russia. And it would certainly include any nations that are looking to intimidate nations around their periphery, regional nations nearby them, whether it be with weapons of mass destruction or I would call it unusual, unorthodox means of intimidating them.

You are part of the world's most feared and trusted force. Engage your brain before you engage your weapon.

What would you do differently as defense secretary to compensate for this record in which the greatest military in the world, as we are constantly told, doesn't get the job done?

Anyone who kills women and children is not devout. ISIS cannot dress themselves up in false religious garb and say that somehow this message has dignity. We're going to strip them of any kind of legitimacy.

The importance of strengthening Euro-Atlantic security: the growing dangers pile pressure on our rules-based international system, so we need to do more to strengthen NATO, the bedrock of our defense - not just upping spending, but making the alliance more agile and more capable of tackling dangers from all directions.

It is mostly a matter of wills. Whose will is going to break first? Ours or the enemy's?

I think the core problem is much closer to recognizing where force is of value, where it is useful, and to distinguish that from situations in which war is not useful or is indeed counterproductive.