But Wind_FURY does have a point, storing your nations money in another nation can have repercussions for you. Or if you look at it from the other side, it does let the nation who has your money control you a bit.
It's a double edged sword.
On one hand this proves the country's solvability and it may be OK to be done in a way a third party stops you selling it all too fast (to protect others), hence not great for Bitcoin (maybe unless done somehow with some x-of-y multisig wallet).
On the other hand, as said, the other country can do things from freezing those funds to even seizing them.
However,
now all foreign currencies are banned in Afghanistan.