Nebuchadnezzar was the supreme authority in the world of his day. Earlier, Jeremiah had warned the kings of Edom, Moab, Ammon, Tyre, and Sidon: that God had given Nebuchadnezzar sovereignty over the entire earth, including the animals ( Jeremiah 27:6-7; Jeremiah 27:14). While the extent of his empire was not as great as those that followed him, he exercised absolute control as no one after him did. [source][source][source]
"For a despot like Nebuchadnezzar, his government was the ideal type and was therefore esteemed as highly as gold. He exercised unrestricted authority over life and death throughout all Babylon. His word was law; no prior written law could challenge his will ( Daniel 2:38)." [1][source]
The Lord referred to Nebuchadnezzar as "king of kings" in Ezekiel 26:7. Nonetheless "the God of heavens" (cf. Daniel 2:18; Daniel 2:28) had given this mighty monarch his position. The king ruled under the authority of a higher, infinitely more powerful ruler. [source][source][source]
"At the time of Creation the right to rule over the earth was given man who was to have dominion over it and all the creatures in it ( Genesis 1:26). Here Nebuchadnezzar by divine appointment was helping fulfill what God had planned for man." [2][source]
It took considerable courage for Daniel to tell the most powerful ruler of his time that he was responsible to God (Elohim). God had given Nebuchadnezzar sovereignty (symbolized by the head of the statue), power (the head"s weight), strength (the connotation of the head on a body), and glory (its value as gold). The head of gold aptly described Nebuchadnezzar. It also symbolized the kingdom over which he ruled. [3] Nebuchadnezzar ruled about45 years (605-560 B.C.), and his empire only lasted another21years. Nebuchadnezzar"s father, Nabopolassar, founded the Neo-Babylon Empire in627 B.C, and it fell to the Persians in539 B.C. So it existed for only88 years. [source][source][source]