What you see as giving good to another country is seen as colonization and domination by the natives. The list of this is endless. Are the Native Americans better off for being virtually wiped out by Europeans? Definitely not. Are many of the countries in Africa that we took slaves from at the same level of living as us today? No. Are the tribes in the Amazon better off? No.
We like to think we have done them a favour, but there is still a lot of resentment to this day. It is no different than if the Philippines was part of Japan today, or Britain's all belonged to Germany. Neither of them positive from where I sit.