It seems the simulation assumes nukes won’t be used. Using nukes against key enemy military targets is likely a key part of our counter attack strategy and bolsters the capabilities of our conventional forces.
Nukes won’t be used. They weren’t used in Korea or Vietnam for good reasons. You better pray we never cross that threshold.
Cyber-war is where it's at. It's all about taking out the financial systems, power generation systems, water, interrupting food supplies, etc.. and making a country implode upon itself.
Of course a rogue country like Iran for example may change that, however our "war" with China and Russia is all cyber now. Anything using our military presence in other countries is nothing more than a physical show of force and IMO will not escalate beyond that.
Any "hot" war with Russia and/or China will start out nuclear with the fist strike.