The hidden hand of the market will never work without a hidden fist -- McDonald's cannot flourish without McDonnell Douglas, the builder of the F-15. And the hidden fist that keeps the world safe for Silicon Valley's technologies is called the United States Army, Air Force, Navy and Marine Corps.

I think that the drama of people rising up demanding their own freedom is one that resonates very deeply with America. I think that President Barack Obama has tried and would like to find a way to relate to the Arab Spring, but I think he also wants to be, rightly, very careful that we don't take it over. It is very important that they own this. He is trying to influence it this way but without, "We're so never going to go to the extreme of Iraq and putting boots on the ground again."

So what am I? I guess I would call myself a sober optimist...If you are not sober about the scale of the challenge, then you are not paying attention. But if you are not an optimist, you have no chance of generating the kind of mass movement needed to achieve the needed scale.

That's right-the striking thing about greenhouse gases is the diversity of sources that emit them. A herd of cattle belching can be worse than highway full of hummers.

In a hyper-connected world where average is over, there is one thing we know absolutely for sure: Every good job will require more education.

Our kids are going to be so angry with us one day. We've charged their future on our Visa cards.

Several technological and political forces have converged, and that has produced a global, Web-enabled playing field that allows for multiple forms of collaboration without regard to geography or distance - or soon, even language.