"... this planet, unique in all the universe in supporting life, ..."
The authors are the good guys and I absolutely agree with their concerns but when I got to that I felt like I had carelessly driven my car off the road. I'll speculate that the sentiment they were hinting at is that should we turn this planet into a radioactive cinder there is no place in the solar system or nearby solar systems to which to flee, if any survivors could even muster the technical competence or necessary energy to do so.
Absolutely right that the danger now is becoming greater than it has been in the recent past. Once again the neocons, those Dr. Strangeloves of the 21st century played a major role in ratcheting up the danger. In their manifesto of 2000 the PNAC identified the end of the cold war through the economic and bureaucratic exhaustion of the Soviet Union and the resultant possibility of a "peace dividend" as a threat to all of their cherished beliefs and stock portfolios.
In effect, the authors of Strategies for Rebuilding Americas Defenses just threw away like yesterday's trash everything that had been learned and agreed upon after two devastating multi-continental wars. And then they engaged in a PR campaign to convince the smug beneficiaries on the winning continent (that would be the US) that their radical suicidal plans were the height of pragmatism. The protection and the promotion of "American values, beliefs, and way of life" were cited repeatedly as justifications for commandeering the national wealth and purpose.
And so what do we see of American values in this year of 2016? We see an American President, who won the Nobel Prize for not being George Bush, midwifing global trade deals which are the very antithesis of democratic rule and human dignity. We see a stable of wanna-be POTUS replacements preaching fire and brimstone with missiles and bombs in their darkening nightmare of guilt-driven fear. And in o-so-many unexceptional ways we see a powerful dark state working to choke off dissent, resistance, and change.
And so the MIC is playing a dangerous game of chicken with the rest of the nuclear-armed world. A conventional offensive military far outnumbering any other pursues the age-old quest for empire on the gambit that no sane people would initiate nuclear Armageddon over these global military transgressions. So much for nukes being a deterrent. They are what they will always be: the end of life as we know it just waiting for the right (wrong) individual to come along and press the buttons.