Argentina did rather more than what would amount to Portugal leaving the Euro.
And many people were very, very angry at them.

I don't recall, though, any army patrolling their borders to ensure that no willing trading partner could trade.
If you are going to entertain those thoughts are likely, well then you can just as well write a scenario where France invades Ireland because of its low company tax rates.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi