An idea is only an idea if it causes unease, debate and reflection. By that standard, Thomas Homer-Dixon's concept of an 'ingenuity gap' is truly a new idea. I can think of no other new concept that so fully condenses all of the challenges we face as a human civilization than the 'ingenuity gap'. Homer-Dixon has found a way to unite all of our concerns about economics, war, population growth, complexity, etc. under a single heading. He is one of an elite group of academics who can write for a mass audience.

It is time to understand the environment for what it is: the national security issue of the early twenty-first century.

If you travel around America you see different sections of highways donated by this or that person, and that's a slow beginning of what may end up being a situation common in the Third World: some sections of highways in wealthy areas are beautifully maintained and other parts are just dirt-strewn potholes.

It is a cliche these days to observe that the United States now possesses a global empire - different from Britain's and Rome's but an empire nonetheless.

Americans are opting out of public venues like the playground and the sidewalk for private venues like the healthclub and the mall. We're living our lives inside one form of corporation or another.

Travel is like a good challenging book: It demands presentness-the ability to live completely in the moment.

While the foreign policy elite in Washington focuses on the 8,000 deaths in a conflict in Syria – half a world away from the United States – more than 47,000 people have died in drug-related violence since 2006 in Mexico. A deeply troubled state as well as a demographic and economic giant on the United States’ southern border, Mexico will affect America’s destiny in coming decades more than any state or combination of states in the Middle East.