Who is the enemy in real terms, meaning aside from the demons in the world?
There is an interesting verse in the book of Revelation where the apostle John is told that he must prophecy again. He has given us a view of the church age in a spiritual sense, but now the second time he gives us a view of the church age during the seven year tribulation with the beast, the Great Babylon, the mark of the beast, etc.
This is the problem that many have, they think that the spiritual realm is not real, they want to see people and guillotines. So, during the tribulation you will see them.
I don't consider Russia and Iran and N. Korea to be our enemy any more than I would consider the belt your dad used when you were punished to be the enemy. They are simply a tool in God the Father's hand. Some people need famine and plague and war to repent and humble themselves. So in that sense the war that is coming to the US will be useful at accomplishing the will of God.
So besides demons I would say our pride and ego are the biggest enemies.
There will be soldiers, there will be tens of millions killed, there will be natural catastrophes like no one has ever seen, there will be plague and famine. But those are all designed to humble us and realize that apart from God we can do nothing.