Change doesn't happen with people sitting on their behinds, getting lazy.

One of the things I love about negotiations is that you have to be able to play it like an orchestra, different instruments for different circumstances. There's sweetness, and encouragement, and cajoling. There's pressure, there's drama, there's ultimatums.

Can I be blunt? Yes. Can I be diplomatic? Yes. Can I concoct a mixture of vinegar and honey when the circumstances warrant? Yes.

The United States really only accounts for about 3 percent of the economic engagement with Russia. Europe is 40 percent, and so Europe's contribution to this pressure is far more than symbolic. It's very practical. And that's one of the many reasons why we have worked hard to remain in close coordination with our European partners.

President Obama is funny, he's thoughtful, he's challenging, he's fun to work with - and it's been an extraordinary privilege.

It may not be what you would've chosen, but we all have a responsibility to be active citizens and shape our system and our future.

If you want change, you have to make it. If we want progress we have to drive it.