We're hopeful that Russia will choose to play a constructive role in supporting ceasefires through their own Astana talks, but also, ultimately, through Geneva. And if we can achieve ceasefires in zones of stabilization in Syria, then I believe we will have the conditions to begin a useful political process.

The increase in the greenhouse gas concentrations in the atmosphere are having an effect. Our ability to predict that effect is very limited.

People who speak up for freedom in regimes that are oppressive are often a threat.

Just remember that a pat on the back is only 18 inches from a kick in the behind.

It's important that we keep our priorities straight. And we believe that the first priority is the defeat of ISIS. That by defeating ISIS and removing their caliphate from their control, we've now eliminated at least or minimized a particular threat not just to the United States, but to the whole stability in the region.

I think the Russians have played now for some time the role of providing cover for Bashar al-Assad's behavior. The alternative explanation that the Russians put forth is simply not plausible.

People who speak up for freedom in regimes that are repressive are often at threat.