Could Israel be destroyed by Iran?

Yes, it is possible that Iran will completely destroy Israel.

The New Testament does prophesy that gentiles armies will destroy Jerusalem, and this prophecy must come true before the Second Coming of Jesus Christ.

It is important that God allowed the Babylonians to destroy Israel completely in the Old Testament.

And God allowed the Romans to destroy Israel completely in the New Testament.

To assume that God will protect Israel against Isran may go against what the Bible teaches.