There’s only one threat model you need to be worried about. This threat model is called “America or Not-America.”
So basically you’re either being attacked by America, or you’re not being attacked by America.
Now if you’re not being attacked by America (which, by the way, is where you want to be) there are some pretty standard defenses you can deploy
Throw some artillery at them, put machineguns near natural lines of approach, and you should basically be fine.
Now on the other hand, if you are being attacked by America, THERE ARE NO DEFENSES AND YOU’RE GONNA DIE
Abandon all hope and just give up. Take the day off, catch a movie, and then you’re gonna die. There’s nothing you can do to out-America America.
These guys have all kinds of things you don’t even have
They have drones, they have satellites that’ll intercept the communication you are using, you don’t have a satellite,
they have guys dropping out of helicopters and you’re on the frisbee golf team. They have night vision goggles, they have guns that shoot around corners. That’s a weird thing, so I don’t think you having a CIWS on your fire base is gonna protect you from all that stuff.