I think we do. I think we do not always do it in an effective way, but we clearly do try to do this. In a sense, you could say that we try to do this more than ever. For a long time, during the Cold War, we had a more "realist" approach to international relations. Our actions were based much more on power considerations than on moral ones. Nowadays, we often act on moral grounds, trying to protect people who really don't matter to us in material terms.
We still think our way is the best and we still try to act as an example to everyone else. That doesn't mean everyone is "buying it," though.