Who is the most advanced race? Places like India, Afghanistan, Pakistan are undeveloped places, wouldn't it be good if the Greeks or the Nordics conquered those places to develop them? The development of the blacks happened when the whites went to Africa. Can't the same happen for undeveloped regions and races?
The development that whites had given to other races through the process of conquering was done, in my opinion, through the paternal mechanism of trying to develop them as a colony under the ruling country. This occurred after the conquering took place, but that does not mean any sort of conquering is a prerequisite to this form of aid. Of course, other forms of aid and cooperation exist beyond this, so again, no reason to conquer.
Just to restate the answer: Do we need to conquer others to help them, or other superiority complexes? The answer is NO! This will destroy racial relations and not truly empower them. To truly grow as people, they must develop by their own hand, not due to force, nor by being excessively given things, either.
We can encourage them and set up positive systems of trade and education, as well as charity, etc, however, any sort of excessive paternalistic behaviors, or outright aggression, will hinder them or anyone. Further, what do we get out this? A misplaced sense of righteous? Easier access to resources? We can get all these things on our own.