Nah. We have memberships in families, neighborhoods, friend groups, local areas, cultural groups, nations, and the whole world. And problems at any of these levels can grow to the point where they affect us, too. And places where the needs are most acute and broad stand the greatest chances of developing to not be as acute of problems anymore and indeed to offer value to the overall world community through trade.
Indeed, the extreme version of what you're saying is why so many only give to their church communities which are insular and isolated. Or to just retain everything.
70% of my giving is domestic, but I think it's nuts to ignore the rest of the world. Yes, things improved in distant lands maybe are harder for me to see and have less of a direct impact on those around me; so discount their benefit some, but that marginal benefit is so much larger...