After the first World War, weary nations hoped world war would never ever happen again, though it did 20 years later. They proposed a League of Nations - an international forum - that would hash out problems before they reached the boilover point. They even included Germany. Alas, the same Treaty of Versailles that proposed the League also decreed that Germany pay the full cost of the war just ended. Of course, Germany couldn't, and the resulting economic strain created chaos (compounded by the Great Depression) from which Hitler emerged, appealing to national pride and a sense of victimization. World War II started, and the League of Nations collapsed.
After the second World War, the League was resurrected in principle, and rechristened the United Nations. Jehovah's Witnesses have pointed to it as the beast of Rev 17:8 -
The wild beast that you saw was, but is not, and yet is about to ascend out of the abyss, and it is to go off into destruction.
It "was," prior to World War II. It "is not," during that war, and it "ascends out of the abyss" (as the U.N.) after that war. It is also described as (Revelation 13:14-15) the "image of the beast," since it reflects the qualities of its component nations. Since the most prominent of these component creates it, they are said to have "breathed life" into it. Beasts are frequently used in the Bible as symbols of human governments, likely for the way they rip and tear and devour each other, and even their own peoples.
Detailed explanations of these verses, and indeed of all of Revelation, are found in the book Revelation - It's Grand Climax at Hand, available from Jehovah's Witnesses. I've previously referred to it here and probably some other places as well.
Now, offhand, a League of Nations - an international forum for peace and security - seems like a good idea. Let nations talk it out, not fight it out, and so forth. And no one has any gripe at all with the humanitarian good such agency has accomplished. The organization is, however, the exact opposite of what the Bible proposes. For the Bible advocates world government by God - God's Kingdom - which is to replace human rulership. It is described here, as God's answer after a long torrent of failed human efforts:
And in the days of those kings the God of heaven will set up a kingdom that will never be brought to ruin. And the kingdom itself will not be passed on to any other people. It will crush and put an end to all these kingdoms, and it itself will stand to times indefinite. Dan 2:44
This is the same government of the "Lord's prayer," named here in Matt 6: 9-10 (NIV):
Father in heaven, hallowed be your name,
your kingdom come, your will be done
on earth as it is in heaven.
People repeat this prayer, usually by rote, and it becomes like the Pledge of Allegiance. They have no idea what it means.
The League of Nations, noble though the idea sounds, advocates world government by man, and this puts it at odds with the Bible. President Woodrow Wilson lead in birthing the new organization. Ironically, he couldn't talk the U. S. Congress into joining. Europe was a long ways away. The oceans had always afforded good isolation, and hopefully, with WWI in the past, they would continue to do so. Let Europe attend to their own squabbling.
The churches, whom you might think would side with world government by God, fell all over themselves to embrace world government by man. The National Council of the Churches of Christ in America lost no time declaring "such a League is not a mere political expedient; it is rather the political expression of the Kingdom of God on earth...." If Congress didn't want to sign up, it wasn't for the churches' lack of effort; 14,450 leading clergymen signed a petition urging the Senate to get onboard with the rest of the League supporters. The Pope, too, pleaded for the League’s adoption. All this in 1919.
Seemingly, the only ones not buying into the hoopla were Jehovah’s Witnesses, then known as the International Bible Students. That same year - 1919 - addressing a convention in Cedar Point, Ohio, J. F. Rutherford, Watch Tower Society president asserted that "the Lord’s displeasure is certain to be visited upon the League . . . because the clergy—Catholic and Protestant—claiming to be God’s representatives, have abandoned his plan and endorsed the League of Nations, hailing it as a political expression of Christ’s kingdom on earth.”
Jehovah’s Witnesses would not abandon “his plan,” even if all the rest of Christendom did. Three years later, discerning that the actual Christ’s kingdom had been established in heaven in 1914, (written about here and here) Rutherford urged conventioneers (it’s an oft-reported speech that all Jehovah’s Witnesses have heard about) to “advertise, advertise, advertise the king and his kingdom” - which is what Witnesses have done ever since.
Thus, establishment of the League of Nations represents a fork in the road. The churches, almost without exception, publicly embraced world government by man. At the same time, Jehovah’s organization publicly took the opposite path, advocating world government by God, in acknowledgement that God’s Kingdom does not come through any consensus of manmade governments. This explains Jehovah's Witnesses' neutrality toward this world’s governments. The churches, meanwhile, are ever convinced that God uses whatever national government they live under, to accomplish his aims. They are forever meddling in political affairs, trying to sway governments to write their own views into law. The actual Kingdom of God means little to them. Their goal is to put a smiley face on existing human governments.
Recommending world government by man or world government by God - this was among the chief differences between the churches and Jehovah's Witnesses back then. It is also so today.