Vague response and foggy analogy. Veterans and military retirees pay into soc sec too. So they would be cut on both. You never explained where the lines would be drawn? AFTER they retire? or those that are just ready to retire?
I expect a broke government to treat their obligations to its citizens similarly.
Military retirees, Retired Civil Servants, Social Security recipients will all receive less.
The best you can hope for is means testing.