This hurling out of heaven happened shortly after the enthronment of Christ as King, according to the watchtower, e.g. w 1995 July 15th page 5
Satan’s influence on earth is temporary. Jehovah will not tolerate satanic rule much longer! Soon the Devil will be put out of action. A new ruler will take control of the earth, a righteous king chosen by God himself. That King is Jesus Christ. Concerning his enthronement in heaven, Revelation says: “The kingdom of the world did become the kingdom of our Lord [Jehovah] and of his Christ.” Revelation 11:15 Bible chronology, together with the fulfillment of Scriptural prophecy, proves that this event took place in the year 1914.— Matthew 24:3,6,7.
The Bible also describes what happened shortly after Jesus’ enthronement. It says: “War broke out in heaven: Michael [Jesus Christ] and his angels battled with the dragon [Satan the Devil], and the dragon and its angels battled but it did not prevail, neither was a place found for them any longer in heaven. So down the great dragon was hurled, the original serpent, the one called Devil and Satan, who is misleading the entire inhabited earth; he was hurled down to the earth, and his angels were hurled down with him.”
What would be the result of Satan’s expulsion from heaven? Those in heaven could rejoice, but what about the earth’s inhabitants? “Woe for the earth and for the sea,” says Revelation 12:12, “because the Devil has come down to you, having great anger, knowing he has a short period of time.” Indeed, the casting of Satan out of heaven has brought woe to the earth. The Columbia History of the World states: “The great catastrophe of the Four Years’ War of 1914–1918 . . . showed the Western world that it could not protect civilization from its own stupidity or evil impulse. The spirit of the West has never really recovered from that shattering.”
The woes of this generation are marked by far more than a shattered spirit. Jesus prophesied: “Nation will rise against nation and kingdom against kingdom, and there will be food shortages and earthquakes in one place after another.” He also foretold pestilences. (Matthew 24:7, 8; Luke 21:11) Moreover, the Bible says that in “the last days” of Satan’s system of things, many would be “lovers of themselves, lovers of money, . . . disobedient to parents, . . . not open to any agreement.” People would also be “lovers of pleasures rather than lovers of God.”—2 Timothy 3:1-5.
Wars, pestilences, food shortages, earthquakes, and a change for the worse in moral values—all such things have taken place on an unprecedented scale since 1914, just as the Bible foretold. They indicate that the enraged enemy of God and man—Satan the Devil—has been cast out of heaven and now must confine his wrath to the domain of the earth. But the Bible also shows that Satan will not be allowed to operate much longer. He has only “a short period of time” remaining until Armageddon, when God destroys the world system that Satan controls.
What will then happen to Satan? The apostle John wrote: “I saw an angel coming down out of heaven with the key of the abyss and a great chain in his hand. And he seized the dragon, the original serpent, who is the Devil and Satan, and bound him for a thousand years. And he hurled him into the abyss and shut it and sealed it over him.” (Revelation 20:1-3) What relief for suffering mankind!