It is not nations that have to repent to cause God to move, it is people. When people sincerely repent God moves on their behalf.
Read: 2 Chronicles 33:12-13
But while in deep distress, Manasseh sought the Lord his God and sincerely humbled himself before the God of his ancestors. 13 And when he prayed, the Lord listened to him and was moved by his request. So the Lord brought Manasseh back to Jerusalem and to his kingdom. Then Manasseh finally realized that the Lord alone is God!