Comment by LorenPechtel

I disagree on air defense inherently being very costly.

Old school was guns. Price per round was cheap. But the expensive missile kills the platform holding the cheap gun, you have to go with missiles. But the drone war is a different beast entirely. Drones can't shoot back. Thus the answer is guns. How well will their light drones fare against a Cessna armed with an automatic shotgun? How would the jet drones fare against a WWII warbird?

Lots of cheap, mobile guns. No meaningful self defense but doctrine is to always depart after shooting.

The naval one is much harder because you're not free to disperse your ship into many pieces. But, still, consider your cannon. Let's step down a bit, cheaper cannon with a 90% kill rate--but you put several of them.