Youre making the MASSIVE error in mixing up timeframes...
Colonialism was not only par for the course back then, it was almost expected. We were started as a colony of Britain ffs, as was Canada (Britain and france obviously, and Russia in the BC part IIRC). After that we had Manifest Destiny which resulted in the rest of the tribes being either pushed West or placed on Reservations.
I'm not saying those were good things, but they were certainly not abnormal for the time period.
It's 2017, not 1492 is my pt. I don't personally feel that the US should serve as the World Police, so to answer your ?, no, we shouldn't be involved in the shit tier economies of Africa, SE Asia and parts of L. A.