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

What Americans cant face is that one of the reasons that the Russians and the Chinese were so impressed with us during the Cold War was the fact that Nixon and Kissinger went on bombing despite public reaction.

What does the earth look like in the places where people commit atrocities? Is there a bad smell, a genius loci, something about the landscape that might incriminate?

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.

The United States is not overdeployed or overextended with deployments in 150 countries on any given year. On any given week we have about 65 deployments.

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.

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.