How does the poem, "The White Man's Burden", justify imperialism to the industrialized world and the unindustrialized world?

The main way in which the poem, "The White Man's Burden", justifies imperialism to the industrialized world and the unindustrialized world is that it implies that it is the "obligation" and duty of white men in developed and rich countries to colonies poorer countries--in order to implement more "modern" and prosperous forms of government.