America is the greatest country on Earth. But because of some of the mistakes that have been made, we, I think, are going to have a lot of work to do in the next administration to restore that sense that America is that shining beacon on a hill.

I think that where I've gotten frustrated during the course of my presidency has never been because I was getting pushed too hard by activists to see the justness of a cause or the essence of an issue.

The president does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation. As commander in chief, the president does have a duty to protect and defend the United States. In instances of self-defense, the president would be within his constitutional authority to act before advising Congress or seeking its consent.

The United States is not, and never will be, at war with Islam.

The single biggest threat that we face is a nuclear weapon or some weapon of mass destruction. What that means is that we have to be extraordinarily aggressive and vigilant in controlling nuclear proliferation.

You are part of the first generation of officers to begin your service in a world where the effects of climate change are so clearly upon us. Climate change will shape how every one of our services plan, operate, train, equip, and protect their infrastructure, today and for the long-term.

I'm not talking about blind optimism, the kind of hope that just ignores the enormity of the tasks ahead or the road blocks that stand in our path. I'm not talking about the wishful idealism that allows us to just sit on the sidelines or shirk from a fight. I have always believed that hope is that stubborn thing inside us that insists, despite all the evidence to the contrary, that something better awaits us so long as we have the courage to keep reaching, to keep working, to keep fighting.