welcome in his country due to sharing risks and stablizing the currency rate. It's not imaginable to a totalitarian regime who used to control everything and make their currency artificially low and squeeze profit with exporting.
One question, why FER is defined as "held by national banks" only? National banks, private banks and speculators are kind of debter-debtees which build up a balance scheme and keep banks from crisises in a certain scale. The number "held by national banks" obviously doesnt make sense to represent this 'sustainability'.