If Daniel had contact with king Nebuchadnezzar, then the book could NOT have been written in the 2nd C BC....... assuming it was written by Daniel.
You are 100% correct. That is the dilemma and discussion among Bible Theologians. I should have said "could have been written as early as..." If you assume it was written by Daniel, it had to be written around the 6th Century during the life of Daniel, Babylonian Empire and King Nebuchadnezzar. Critics will argue that it may have been written as late as the second century which makes it written after many of the events of the Persian and Greek Empire. The Armenian and Hellenistic language does make the 2nd Century writing compelling. Either way, the very fact and it is a fact that the predictions did come to pass even beyond the Persian and Greek Empires is without argument at least to be considered.
Without getting all biblical - Deuteronomy 18:21-22 sums it up pretty well. And if you say in your heart, ‘How shall we know the word which the Lord has not spoken? When a prophet speaks in the name of the Lord, if the thing does not happen or come to pass, that is the thing which the Lord has not spoken...
