I also believe that after the rapture, that the unhindered, evil violence of islam will be a tool used by God to pour out His wrath upon the world.
There is Biblical and historical precedence for God using the most ungodly for His purposes.
Have you not read that God uses his angels to pour out his wrath upon the earth? Read Revelation 8, 9, 15, 16. The ungodly will not be his "agents", they will be the objects of his wrath.