Practically speaking, if you’re still seriously worried, take a look at contractor jobs for the DOD! What they need now is probably what they’ll need during the war:
- tech buzzwords: C/C++, embedded programming, static code checking, data pipelines in general
- industry buzzwords: satellite ground resource management / telemetry, tracking, and control (GRM/TTC), Command and Control (C2), signals intelligence (SIGINT), bombs
if you are already in a desk job for an war critical comany or organization, then they would take another person first.
Drone-related stuff might also be good.
Get a back back or bad knees. Work on getting really fat. Asthma helps.