Why is the biblical god powerless against iron chariots?

I want to make a joke and tell you that iron chariots are very strong but actually in Judges God was not fully with them, the book merely passively records many sins while only saying that they did what was right in there own eyes. Even when Moses went back into Egypt the suffering of Israel was prolonged for God to make His point with The Egyptians. However afterwords the only point to be made was the list of Blessings & Cursings in Deuteronomy; under Moses & Joshua this was kepted to a minimum but immediately afterwards things fell apart.