Nothing particularly out of the ordinary happened in 1914, when you look at a long sweep of world history. This so-called "World War I" was not the first real world war in the sense that virtually all nations participated, for what is called "World War II" was really the first of those. WWI was really a European war in which the U.S. finally participated. Sure, there was fighting outside Europe, but it was almost entirely within various European colonies, so that was just an extension of the war on European soil. If one insists on calling this great European war a "world war", then other wars qualify just as well. For example, the Hundred Years War killed far more of a percentage of the population of Europe than WWI did, and it involved just about every European nation. For a comprehensive look at these matters, see Carl Olof Jonsson's The Sign of the Last Days: When?, available from www.freeminds.org and Commentary Press.
Keep in mind that the Watchtower Society predicted, not just a war for 1914, but a total world revolution that would result in the complete destruction of all human institutions. They predicted plenty of other things for 1914. Not a single thing came true. The only reason the Bible Students didn't fold up shop after 1914 was that they managed to convince a few people that their predictions had succeeded, by ignoring most of their predictions and focusing on what was until WWII called The Great War. If the war hadn't luckily come along, they'd have folded just as surely as most other apocalyptic sects folded after their major prediction failed.
As for the Society's claim that things are radically different after 1914, to a certain extent that's true, but when examined objectively one finds that the changes are evolutionary, not revolutionary. Sure, some peoples' attitudes about life changed as a result of WWI, but no more so than attitudes changed as a result of the 9/11 WTC disaster. The Society quotes a number of supposedly objective historians to the contrary, but other commentators have correctly noted that such statements are more the product of wistful thinking about a non-existent golden childhood on the part of these people than an objective look at historical change. The fact is that almost everyone forgets a lot of the hardships of childhood and only remembers the golden moments. That's the way humans work. Careful researchers, though, know very well that a pre-1914 "golden age" existed only for the very wealthy, and that certainly disappeared as the gulf between the incredibly rich and the incredibly poor narrowed considerably after WWI, and especially after the Great Depression ended. The condition of the average citizen in most countries, especially Western countries, improved considerably after this time period.
So, looked at objectively, 1914 was a great big fizzle for the Society. No one besides today's JWs gives it any major heed at all. It was a significant date, but there have been many equally or even more significant dates.
AlanF