You worked for it and earned it and you can receive it as long as it is available no matter what country you decide to live. If you moved to Germany tomorrow, you should be able to draw your retirement. Many people have "dual citizenship" and live in another country. You may pay taxes back here in the U.S. but you can still draw your retirement pay. If states secede it would be like they were another country and the same should apply. I checked on that years ago when I considered moving to another country for a period simply for educational purposes.One thing that is missing in all of this.
We CKW and myself) have paid into SS since we were kids. It is not all of our retirement but a good portion as CKW is on a well deserved disability from her SS and I receive mine. When the dip 's and politicians crashed the economy in 06/08 we lost most of whet we had for retirement and never recovered. It would be a struggle if that went away and many due to poor planning etc would surely perish.
As we paid into this rolling Ponsey scheme for 50+ years to just throw in the towel is not something I or a zillion others is ready to do.
I hate it but there it is.