The answer is a resounding YES!!
20th century history is full of genocide resulting from the lack of action from "moral" nations. The UN created Israel as a direct result of the post war guilt over inaction against German persecution and genocide. Who can forget the horrors of communism, the Stalin purges which may have exceeded the Holocost in actual victims, the killing field of Pol Pot's Cambodia and China's "agricultural reform"?
In fact the question isn't whether we were right, it is "Why isn't the UN or some other country doing more to stop immorality like what is happening in the Congo right now"?