[tropo]

Consider Melbourne, FL. It's in that size range.

It has Northrop Grumman, Lockheed Martin, Harris, Embraer, GE Transportation Systems, GE Energy Management, FightLite Industries, Thales, Raytheon, DRS, and a bunch of little cyberwar startups.

So there is plenty related to aircraft, cyberwar, and generally all sorts of engineering/manufacturing/etc. for government (especially military) purposes.

Working in a specialized industry is fine. The city is specialized.

OTOH, moving elsewhere is not the end of the world. There are many other fine small cities all across America. You don't have to live where there is more than one job suited for you. Moving every now and then will let you experience more of America.