Evil does exist in the world. A non-violent movement could not have halted Hitler's armies. Negotiations cannot convince al Qaeda's leaders to lay down their arms. To say that force may sometimes be necessary is not a call to cynicism - it is a recognition of history; the imperfections of man and the limits of reason.

One of the great things about the United States is that when it comes to world affairs, the president obviously is the leader of the Executive Branch, the Commander-in-Chief, the spokesperson for the nation, but the influence and the work that we have is the result not just of the president, it is the result of countless interactions and arrangements and relationships between our military and other militaries, and our diplomats and other diplomats, the intelligence officers and development workers.

There have been times where, let's say on LGBT issues, when we were trying to end Don't Ask, Don't Tell, and I got the Pentagon and Bob Gates, a Republican holdover from the [George W.] Bush administration, to authorize a study of how you might end Don't Ask, Don't Tell, headed up by Jeh Johnson, who at that time was a council to the Justice Department. And it was going to take a year to conduct that study, issue a report, and figure out how it might be implemented, what effect it would have on unit cohesion and military effectiveness.

If there's one thing I would like to see, it'd be for us to be able to price the cost of carbon emissions.

I've made it clear for years that the threat from Iran is grave.

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With respect to some of the specific legislation or initiatives that I've made, it's true that Republicans often opposed these things. Sometimes they opposed them because I proposed them. Now that they are responsible for governing, I think they'll find that reversing them would be counterproductive.