I really doubt Sweden could put Finland back together. The costs would be too much. That, and the fact that costs aren't the only obstacle in your way. You've got Sven up north and he really likes his independence. You could give South Finland aid, sure. Maybe both Finlands could get aid. You'd certainly gain the hearts of some people who'll appreciate it. But Sweden is not capable of rebuilding a nation on its own. At best, you could gain some good-guy points and the support of some people, but you are not going to be able to turn the country around without destroying your own. And some potatoes aren't going to convince the South Finns to join Sweden, either.