So then... Who or what's holding back or keeping lawlessness and the lawless one back? God is keeping it back! And He'll do so, in His timing and by His orders, until the Antichrist arises out of the midst of the sea (Revelation 13).
"...all that dwell upon the earth shall worship him (the beast/the antichrist/ worldwide secular ruler), whose names are not written in the book of life of the Lamb slain from the foundation of the world. If any man have an ear, let him hear. He that leads into captivity shall go into captivity: he that kills with the sword must be killed with the sword. Here is the patience and the faith of the saints." (Revelation 13:8-10)
God is in control... even in an out of control world. I'm reminded of Revelation 9:2 "so the four angels, who had been prepared FOR the hour and day and month and year were released to kill a third of mankind" (Revelation 9:15).
And... "Then a white robe was given to each of them; and it was said to them that they should rest a little while longer, until both the number of their fellow servants and their brethren, who would be killed as they were, was completed" (Revelation 6:11).
Both of these messages reveal the fact that God knows precisely and specifically when and how and what He's doing and what's yet to come for those on earth and heaven. Everything and everyone serves His purpose, whether they know it or not.