In my opinion, wars to high scale (like a WW III) must only be made by countries who are very rich (Resources, technology, population, economy, weapons, allies) and with a strong culture and a powerful ideology (see the "democratic ideal" of the US, and the "authority and race" of the nazis) to draft the masses and the masses of the entire world towards it.
Wars in large scale in the modern world are not from religion, so I didn’t think that middle east would be a threat, it would be a war in the middle east but I doubt it could be a WW. Wars in the modern world are for economical power and the two nations in aim are China and the U.S.
China is strong, has a great population, has great scientists, a lot of money and controls the trade of the entire world, also have a powerful heritage and a strong ideology. In my opinion these are the events of the possible war:
1. Taiwan made a referendum to decide if they want to join China.
2. China manipulates the information, but Taiwan decides by a narrow election his own independence from China.
3. The U.S. announce that they will support the rising “democracy” of Taiwan from the seats of the U.N.
4. China use his veto in the security council and the U.S cannot condemn China.
5. revolts hosted by Chinese leaders in Taiwan creates unrest in the island, the army of Taiwan is unable to control the masses, there were fires in Taipei, massacres in the Island and bloodshed in all the country.
6. The U.N. try to dispatch a security force but China stops the decision again.
7. With the “excuse” of pacification China invades Taiwan, the strong policy of China stops the revolts, but the press is unable to see the truth behind the smoke courtain.
8. Due to international rejection to the invasion China accepts to retreat his troops but only after a new referendum.
9. In the new referendum Taiwan voted in favor of China, Taiwan is now a part of China again. The international powers avail the process but US is silent.
10. Years later a referendum in South korea is voted against unification, North Korean soldiers fire in the line that divide the countries and the war is again on march (they never signed a peace treaty but a truce)
11. U.S. declare himself Neutral, because his people don’t want a new war and the congress supports this position, the republican faction is weakened because the abuses in Guantanamo and the wars of Afghanistan and Irak.
12. China declares himself Neutral. But in the U.N. is the voice of North Korea.
13. Europe declares himself Neutral.
14. Japan declares himself Neutral, but give economical and tactical support to South Korea.
15. North Korea threat Japan “If they support our enemies, then they are our enemies” says Kim Il Sung II.
16. Japanese parliament approves a constitutional amendment, the prohibition to enter in War that general Mac Arthur includes in the constitution after the WW II is suppressed.
17. The JSDF (Japanese Self Defense Force, a little army that Japan possessed since the prohibition to raise an army after the WW II) signed a contract with Boeing and North American Titan Corp to acquire weaponry. “It’s only for the protection of our citizens” says the prime minister.
18. The NATO says that its ready to enter the war if there’s a nuclear launch.
19. After a series of victories North Korea attacks a merchant ship of Japan.
20. Japan declares War on Korea.
21. Japan Invades North Korea, China sends an ultimatum: “Japan must retire his forces to the parallel 38º”.
22. Japan march over Piong Yang.
23. China declares War on Japan.
24. The U.N. condemn China, China use again his veto.
25. The Euro parliament is the voice of the pacifists, and announces economical sanctions to both Japanese and Chinese.
26. In a bombard over Japan “accidentally” the Chinese MIG’s bombard an American base.
27. CNN says: “Pearl Harbor and this bombing are the same”
28. U.S. declares war on China
It's pretty fun to do this, but is only fictional and for inspire a laugh in the reader
. Its obvious that the War will not happen of this way, but i Think that the war would be China against EEUU