Daniel later explained to Nebuchadnezzar that this “Stone Kingdom” was the Kingdom of God. For God, declared Daniel, would destroy the “golden” Babylonian World-kingdom of which Nebuchadnezzar himself was the “head.” After the destruction of Babylonia, its remnants would be amalgamated into the succeeding lesser and “silver” kingdom, namely the “thorax”-like dual empire of the Medes and the Persians (with its two “arms”).
This second kingdom, after its destruction, would be amalgamated into the subsequent “kingdom of brass which shall bear rule over all the Earth.” This would prove to be the “abdomen’ kingdom of Alexander the Great of Macedon in Greece. That, after his death, was destined to divide up into four lesser Hellenistic kingdoms, as is clear from Daniel chapters seven & eight.