Putin is a KGB guys who thinks hte worst event in history is the fall of the Soviet Union. He wants to reconstitute the Soviet Empire.
The Soviet Empire was still in place, and ruled over by Gorbachev as a card-carrying communist, when Reagan made peace with Gorbachev. If Reagan could negotiate and shake hands with Gorbachev - who ruled over the whole of Eastern Europe, the balkans, Ukraine, Georgia — Trump can negotiate with Putin, who is president of only Russia, and who is a professing Christian.
Putin is our enemy and we need to be very careful in our dealings with him.