Jer. 18:7-8 At what instant I speak concerning a nation, and concerning a kingdom, to pluck up, and to pull down and to destroy it, if that nation against whom I have pronounced, turn from their evil, I will repent of the eviltht I thought to do to them.
9-10 And at what instant I shall speak concerning a nation, and concerning a kingdom, to build and to plant it, if it do evil im my sight, that it obey not my voice, then I will repent of the good, wherewith I said I would benefit them.
God seems pretty clear about how he deals with nations.