I left the US and retired in 2011 with ZERO pensions and $1000 in rental income. In the 8th month of 2015 my military reserve income kicked in.
So no, I had no “fat govt pension” providing for me. The fat govt pension was about 1/2 of what I would have received if active duty.
So when the us government and banking systems fall...you’ll be in some foreign land with no money coming in from your defunct country...hope you’ve got a good stash of local currency where you are at.