Good evening the New Jerusalem is prophesied to be established during the millennium and has a definite goal. The kingdom will continue to thrive as the mountain of God during that time, Isaiah 2:2–4. The Government will direct and announce decrees that comes from God that fulfils all the purposes for the kingdom's establishment, Revelation 21:2–4. All this will happen to begin the millennium and will continue until all the subjects have been given salvation because it is one of the goals of the kingdom.
When the final trumpet blast occurs, it will be at the end of the thousand years all of the goals of the kingdom will have been completed and the people will be prepared to approach the final test of their faith. When that time comes the alter ego of God called Satan, who has been 'restraint' during the thousand's years will come back again to test all the people again to create a battle called Armageddon, Revelation 20:1–8. Will the kingdom dissolve and go way from the earth and its subjects after 1,000 years?
Daniel 2:44
Living Bible
44 “During the reigns of those kings, the God of heaven will set up a kingdom that will never be destroyed; no one will ever conquer it. It will shatter all these kingdoms into nothingness, but it shall stand forever, indestructible.
Update on the post 10/24/22
The Russia - Ukraine war was also a test that was allowed to be created because of mankind's error. Since it was noted that people were imperfect the war escalated into use nuclear weapons despite the fact that it could kill all life on earth. Again, this was done as a test called the Great Tribulation but not Armageddon which is after one thousand and called the final test.
