Uh....actually, he gained the support of the other European powers by making a wide range of different promises, such as....
“ also secretly told British merchant houses that if he was given formal control of the Congo for this and other humanitarian purposes, he would then give them the same most favored nation (MFN) status Portugal had offered them. At the same time, Leopold promised Bismarck he would not give any one nation special status, and that German traders would be as welcome as any other.
Leopold then offered France the support of the association for French ownership of the entire northern bank of the Congo, and sweetened the deal by proposing that, if his personal wealth proved insufficient to hold the entire Congo, as seemed utterly inevitable, that it should revert to France. On April 23, 1884, the International Association's claim on the southern Congo basin was formally recognized by France on condition that the French got the first option to buy the territory if the association decided to sell. This may also have helped Leopold in gaining recognition for his claim by the other major powers, who thus wanted him to succeed instead of selling his claims to France.[18]”
en.wikipedia.org
Trying to equate late 1800s colonialism to anything the US does today is beyond dumb