It's important to be reminded again of where we are in the flow of the book of Revelation. We are continuing our study of the interlude between the sounding of the seven trumpets and the pouring out of the seven bowls of Gods wrath. Remember, each of the "sevens" (seven seals, seven trumpets, seven bowls) takes us right up to the very end of time. These three "sevens" pile up on top of each other, both in speed and in intensity.
But in this interlude of the visions (not an actual interlude in the events) John is being given a picture of the meaning of the things that are about to be revealed about the pouring out of God's wrath and the end of the age. First, John has been shown that this is a spiritual conflict that has been unfolding. This is the importance of chapter 12. This is not just a military conflict, or an economic conflict, or a political conflict. Satan (that Dragon) is determined to crush the work of the Messiah, Jesus Christ. John is only seeing the outward manifestation of an age-long struggle between the kingdom of God and the kingdom of Satan.
Second, John has been shown that while the real nature of the struggle is spiritual and invisible, Satan will manifest himself visibly, particularly in the end-time efforts of the antichrist and the false prophet. The antichrist will stand on a political structure much like those kingdoms Daniel wrote about in Daniel 9. The false prophet will work in a religious system that will prompt worship of the antichrist and his power. Hence the importance of Revelation chapter 13. We begin to see the kinds of agencies or outward means Satan will use as this battle intensifies.
Now, just before the unfolding of the very end, John is once again given a vision designed to assure him and the church of God's ultimate control and victory over the affairs of the end-times events. History is all still in God's sovereign hand.