I guess what we're learning about war is:

1) In a land battle, asymmetric warfare (use of cheap drones, mines, guerilla tactics, etc) are becoming quite effective (especially when defending your own real estate...see Ukraine). However,

2) If you want to be an international superpower, its still about projecting power at sea.

a) Russia sucks at this

b) The US still has an advantage but

c) In a few years, China may have more hardware, plus carrier-killer missiles

3) Everyone is worried about cyberwarfare but:

a) How long could SCADA systems be impaired before operators restore manually (ie Ukraine seems to have survived utility attacks)

b) Hard-currency transactions are preceded by about 48 hrs of "paper transactions", and have a type of circuit-breaker.

c) The big worry here may be GPS communications, which if disrupted, could disable planes/missiles en masse. A secondary emergency communications network is needed.

d) Russia probably sucks at all this too, but they excel at "nuisance hacking"..