Well we can speak of a nation as of it has a morality but it masks that fact that this just an abstraction. Nations are composed of people all having their own views on good/bad.
But I guess we can agree that decisions and actions carried out by or under direction from a country's leaderhip can be simplied as being that country's actions.
Some actions might qualify as "good" and some as "evil" so in that sense every country exhibits both.
The easiest way out of this to try to objectify the matter and that's where the UN comes in. Rather than emotive, subjective "good" and "evil" we can talk of legal or illegal insofar as the UN charter defines things and that's largely how I look at it.
There are other ways but they lose their objectivity unless we invoke some external authority.