[Faceman]

I say in a global economy other nations problems are our problems too.
It depends on the country of course.
It's the same question as: "If somebody else has a problem should I get involved" It depends.
In many cases it's self-evident (e.g. should I help somebody asking for directions, lend a hand to someone who has tripped and fallen,...) in some it depends on your own situation (e.g. don't try to stop an armed robbery when unarmed and weak yourself).
The only main difference between the behaviour of countries and the behaviour of people within countries is that there are no binding laws in international laws, it's just a set of contracts. So there is no equivalent for "calling the police" because there is no "world police".

IMHO complete isolationism in this day and age is a tad unrealistic, but you also can't jump in every time because you've got to respect countries' sovereignities and ponder whether they may figure out their problems rather quickly themselves.