The definitions are slightly different than you would find on Wikipedia:
Risking Nuclear Strikes:
DEFCON 1- All-out nuclear war, mutually-assured-destruction and everything.
DEFCON 2- Nuclear strike about to happen unless something deescalates.
DEFCON 3- Nuclear strike imminent
DEFCON 4- Nuclear strike occurring only in retaliation
DEFCON 5- All out war, high death toll
DEFCON 6- War occurring; at standstill
DEFCON 7- War occurring, doing well
DEFCON 8- War occurring, not needing to use reserves
DEFCON 9- In peacetime, war imminent; MSR able to mobilize in 15 minutes
DEFCON 10- In peacetime, threat of war looming, MSR able to mobilize in 30 minutes
DEFCON 11- In peacetime, war unlikely, MSR able to mobilize in 1 hour
DEFCON 12- In peacetime, war unlikely, MSR able to mobilize in 12 hours
DEFCON 13- In peacetime, nation not interested in international affairs, war extremely unlikely, MSR able to mobilize in a week