Does the U.S. need an enemy?

Mikhail Gorbachev said that by dissolving the USSR, he was going to do a terrible thing to the U.S. in depriving us of an enemy. Is there any truth to this? I grew up during the Cold War, and there was a sense of comfort in knowing who the enemy was.

There is something not quite right about all the partisan bickering and the rise of Donald Trump. I did a Web search and found this article. It is kind of long but worth skimming. I find of interest the role that Carthage played for the Roman Republic. What are your thoughts?