What does 911 have tp do with the unborn? I thought 9/11 was an attack by Islamic terrorist? Either you are a troll or a victim of ignorant theology. There is no covenant with the US and God. God will judge all (individuals) according to the New Covenant.
If you want to have a discussion of theology, we can do it. God did not just judge Israel. Foreign nations were God's rod against Israel, however. Then God judged those pagan nations in turn.
Read the minor prophets. I do not know the reasons why God brings his judgments and when. I cannot for certain say what 9/11 was judgment for. I do know that the murder of innocents brings his judgments.