I will not speak to Vladimir Putin personally until we've rebuilt the 6th Fleet a little bit right under his nose; rebuilt the missile defense program in Poland right under his nose; and conducted a few military exercises in the Baltic states.

So what will define greatness for your generation? I believe it is to use the knowledge that you have earned here to find ways, not only to connect to computers, but to connect to people; not only to bridge gaps in science, but to bridge gaps between cultures; not only to use numbers and formulas to create, but to use words to lead, and in the process, to close that canyon between ignorance and understanding.

Leadership is all about unlocking the potential in others.

To wage war, we need a commander in chief who has made tough calls in tough times and stood up to be held accountable over and over, not first-term senators who've never made an executive decision in their life.

As president, the first thing I will do is secure the border. It will take money, manpower, and technology - but most of all, it will take political will.

We also know that ISIS is recruiting who are not in those databases. So of course, we're going to miss them. And then we now learn that DHS says, "No, we can't check their social media."

You take unacceptable risk, you have to be prepared to face the consequence.