Our mother once told us that, if we can't say anything nice, it's best not to say anything at all. So… yeah, about this speaker... he certainly seems… enthusiastic?
We know, we know—by today's standards, this dude is pretty awful. Anyone who thinks that white men can "save" everyone else in the world by forcing them to adopt a European way of life is both racist and, well, pretty dumb. That much is clear to us now. And, if there is any good news here, the fact that our modern eyes can see this as so plainly racist is an encouraging sign of progress. In fact, not too long after this was written, Kipling himself fell from literary favor as folks began to realize just how wrong some of his ideas were.
But are this speaker and Rudyard Kipling one and the same? It's never a good idea in poetry to mix up your poet and your speaker, as a poet will often speak through an invented character. And there is an interpretation of this poem out there which reads it as sarcastic. In other words, Kipling may have been criticizing American and European imperialism by making this poem's speaker so obnoxious.
Still, that doesn't quite square with some of Kipling's other works (check out "Calling Card" for other examples), which were equally in favor of white people taking over the homes of less "civilized" brown and black people in order to show them how to properly drink afternoon tea, iron their trousers, and a whole host of other things that they could have lived without.
At the end of the day, then, we have a speaker who goes off on an impassioned, racist rant about the white man's obligation to take over the world. He doesn't see it in terms of overpowering others, though. (Racists are almost always blind to complex things like social power.) He sees it as both a moral duty to "help" and an important rite of passage to maturity. Even if we can overlook his racism, though (and we can't, nor should we), it's unclear about whom he's most concerned: white men or the local native peoples. He certainly seems more focused on rooting on the white guys, treating the other people as objects to prop up white manhood.
In the end, we think we'll just have to take our mother's advice about this guy.