If God is keeping silent (not intervening) during the seven trumpet plagues, then who is bringing on the plagues? A number of features of the plagues make it obvious that the trumpets are Satan’s activity, a counterfeit of the seven last plagues.
First of all, the trumpet plagues affect a third—a third of the sea, a third of the living creatures, a third of the ships, a third of the rivers and springs of water, a third of the sun, moon and stars, killing a third of mankind (Revelation 8:8-12, 9:15,18). In Revelation 12:4 we see that it is the fiery red dragon, Satan, who “drew a third of the stars of heaven and threw them to the earth.” Damaging a third indicates satanic activity.
God, being love, must by His very nature share and give; even the Godhead itself is a Trinity, in which the outgoing principle of love is expressed among the three members. One-third is the anti-trinity, reflecting Satan’s desire to have all the glory himself, sharing with no one. Thus one-third is a Satanic number, and the trumpets with their destruction of “a third” show the results of his activity.
In chapter 7 we saw an "angel ascending from the east having the seal of the living God" restraining "four angels, standing at the four corners of the earth holding the four winds of the earth." We saw that the four angels are agents of Satan who will be "granted" permission ot harm the earth, sea and trees (see 7:1 The Four Winds). The seven trumpets begin with disasters that harm the earth, sea, and trees, showing that they are a result of the activity of Satan's "four angels."
Moreover, the “king” in charge of the fifth plague is specifically identified as “the angel of the bottomless pit,” Satan (Revelation 9:11). The sixth trumpet plague involves the release of “the four angels who are bound at the great river
The last three trumpets are called "woes" (Revelation 8:13, 9:12, 11:4). The only other use of the word "woe" in the Book of Revelation shows that the source is the activity of Satan—"Woe to the inhabitants of the earth and sea! For the devil has come down to you, having great wrath, because he knows that he has but a short time" (Revelation 12:12).
Finally, one of the main purposes of trumpets in scripture is to warn God’s people of the approach of their enemies. “And I saw the seven angels who stood before God; and to them were given seven trumpets” (Revelation 8:2). Angels are blowing trumpets, warning God’s people that Satan, who has to a certain extent been bound, or restrained (as pictured by the “four angels standing at the four corners of the earth, holding the four winds” Revelation 7:1) is now going to be loosed and allowed to bring destruction. The fact that God does not restrain Satan is called “silence in heaven.” It is analogous on a world scale to what happened in the Book of Job—Satan challenged God, and so God gave him "permission" to try to prove his point by attacking Job ("Behold, he is in your power” Job 1:10-12). With the trumpets Satan will use an expanded strategy: instead of simply attacking God's people directly, as Satan did with Job, he will also create general chaos and destruction which will be attributed to God's faithful children, in an attempt to make them targets for persecution so as to destroy their faith destroy the faith of God's children.
 Revelation 16:12
 "They have blown the trumpet and made everyone ready" (Ezekiel 7:14). See also Nehemiah 4:18-20, Jeremiah 4:5,6,19-21, 6:1, Ezekiel 33:1-6, Joel 2:1-12.
 See Appendix 8 for a discussion of the Great Controversy in the book of Job. Even when God allowed Satan access to Job, he still limited his destructive activities (“all that he has is in your power, only do not lay a hand on his person…Behold, he is in your hand, but spare his life” (Job 1:12, 2:6). Likewise, in the time of trouble, Satan will be released, but will still have limits (for example, in the fifth trumpet he can only harm “those men who do not have the seal of God on their foreheads” Revelation 9:4).
 God accepts responsibility for the destruction he allows Satan to bring about. It was Satan who “went out from the presence of the Lord” and destroyed Job’s property and his children, and yet when he returned to again accuse Job, God told him “you incited Me against him, to destroy him without cause” (Job 2:3). The ultimate example of God taking responsibility for the sins of His creatures is Jesus taking upon himself the sins of the world and dying the second death in the place of sinful humans.