Besides the points I already discussed, Stephens claims that unless "the west" is willing to recolonize, it should be obliged to stop pretending that it cares about problematic countries.
I would make a different case: Unless "the west" is willing to undertake a significant increase in legal immigration and/or reduction in barriers to imported goods, it should be obliged to stop pretending that it cares about the people living in problematic countries.
At least allowing greater immigration and lowering trade barriers are things a western country could actually do, and we know they would provide incredible help.
Suppose that Canada announced it was going to make Ivory Coast a colony. What would happen? How would that work out for our northern neighbor?
Sadly it probably wouldn't be much less controversial (at least inside Canada) than an announcement that Canada was going to materially increase it's allowed immigration from sub-Saharan Africa.