What will happen to my shares if country where I have my broker stop exists?

Let’s suppose I’ve bought some shares on NYSE (New York Stock Exchange) and I did it through my broker X in some country A. Then a disaster had happened in country A (volcano eruption, war etc.) and country A stop existing and so broker X, because it has only license and offices in country X.

1. What will happen to my shares which I bought through broker X, can I recover them somehow in USA?
2. If it’s become clear that country A will never exist again, can NYSE emit shares bought by broker X again?