The interpretation changed (or was interpreted depending on the context of the literature) a couple of times. Trust me, the next new light will be that the feet are Iron = America and Clay = China. This would allow for the strong world power that was shattered by a soft economic element but both world powers would need each other to exist.
After that, when the US fails (within a few decades when we all speak Chinese) the Greek world power will not be a significant world power anymore since they never really had a strong impact on Jehovah's people and thus the legs of iron were America and China the feet of clay and iron as they are strong as iron but the communistic aspects of this power make them open for widespread corruption and thus these are the 'soft' elements. We will still be living in the time period of the feet and the rock is about to hit the feet so Armageddon should be really close now. Sorry for the last 300 years of speculation where the Holy Spirit was wrong but the light keeps on getting brighter like a strobe at the disco.
Within 5 world powers the statue would've come into existence at 1914 and thus the head of Gold is America as foreshadowed by the king of Babylon.