What interrupts the eternal kingdom, and what happens after the interruption?
The eternal kingdom is interrupted when Satan is released for a little while. After that brief release, the new heaven and the new earth come, and the kingdom continues onward into eternity. The kingdom itself shall not pass away or be destroyed; God the Son establishes His rule and reign forever.
Les explains that God the Son comes before God the Father as He is about to return to earth, smite the Gentile empires that have been on human history for 2,600 years, destroy them so they disappear from view, and set up His kingdom, a dominion that shall not pass away because it is eternal. Les notes it will be interrupted again when Satan is released for a little while, but then comes the new heaven and the new earth, and the kingdom just continues on into eternity. Finishing the verse, his kingdom is that which shall not be destroyed; there He has His rule and reign.