Sorry, some military support functions are not on military grid...You are mistakenl
And tho you are sure, here are two articles, One on Real Clear Defense website, one in Forbes refuting your “I am sure” comment...
https://www.realcleardefense.com/articles/2018/04/12/future_warfare_protecting_the_grid_113317.html
I could find more, but I have things to do and you have provided only your opinion as fact.
From what I have read, I strongly disagree with your premise and I strongly believe that hardening entire power grid is a National Defense issue, and we are fools for ignoring our vulnerabilities and do so at our peril.