Individuals cannot join the UN only sovereign nations. Groups can associate with the UN as NGOs, non-governmental organizations but must support the charter of the UN which has a clause that they support any military actions by the UN.
Ditto, congregations that rented buildings that displayed the flag or holiday decorations, did not take them down. I noticed that many convention site buildings that are rented, have flags displayed and I have never seen jws take them down.
Also, if a jw put up and took down the flag each day where they worked, that was fine unless there was some ceremony.
*** w02 9/15 p. 25 “Salvation Belongs to Jehovah” *** Hold a Good Conscience”
After describing the ineffectiveness of man-made objects of veneration, the psalmist said: “Those making them will become just like them, all those who are trusting in them.” (Psalm 115:4-8) Obviously, then, any employment that directly involves manufacturing objects of adoration, including national flags, would be unacceptable to Jehovah’s worshipers. (1 John 5:21) Other employment situations may also arise when Christians respectfully show that they worship neither the flag nor what it represents but only Jehovah.
An employer, for example, may ask an employee to raise or lower a flag displayed at a building. Whether an individual would do so or not depends on his personal view of the circumstances. If raising or lowering the flag is part of a special ceremony, with people standing at attention or saluting the flag, then performing this act amounts to sharing in the ceremony.
On the other hand, if no ceremony accompanies the raising or lowering of the flag, then these actions constitute nothing more than performing such tasks as preparing the building for use, unlocking and locking the doors, and opening and closing the windows. In such instances, the flag is simply an emblem of the State, and raising or lowering it among other routine tasks is a matter for personal decision based on the dictates of one’s Bible-trained conscience. (Galatians 6:5) The conscience of one person might move him to ask his supervisor to have some other employee put up and take down the flag. Another Christian might feel that his conscience would permit him to handle the flag as long as no ceremony is involved. Whatever the decision, true worshipers should “hold a good conscience” before God.—1 Peter 3:16.
There is no Scriptural objection to working in or being in public buildings, such as municipal offices and schools, where the national flag is displayed. A flag might also appear on postage stamps, automobile license plates, or other government-produced items. Using such objects does not in itself make individuals participants in devotional acts. What is significant here is, not the presence of a flag or a replica thereof, but how one acts toward it.
Flags are often displayed on windows, doors, cars, desks, or other objects. Clothing with the motif of a flag imprinted on it can also be purchased. In some countries, it is illegal to wear such items. Even if doing so would not violate the law, what would it indicate relative to a person’s position with regard to the world? Concerning his followers, Jesus Christ said: “They are no part of the world, just as I am no part of the world.” (John 17:16) Not to be overlooked is the effect such an action could have on fellow believers. Could it injure the conscience of some? Might their resolve to remain firm in the faith be weakened? Paul counseled Christians: “Make sure of the more important things, so that you may be flawless and not be stumbling others.”—Philippians 1:10.