I'd have to go with whats going on in Korea right now. With North Korea setting a nuke off underground and South Korea moving their missles to the border with North and all of that.
There are too many possible scenarios of the start of WWIII. I've researched the crap out of this topic, as WWIII is the background context of my Science Fiction Novel. Have you researched the topic yourself? If you have, I reckon you'd know that this question can't be answered simply. You basically roll the dice and pick which scenario will best suit your narrative.
I wrote 2 different sci-fi novels so far whose historical background is WW-III and i have one more i am currently working on, and every time i use different events as a basis for it. You can use any one of the ideas mentioned already here, you can use two, heck you can use all of them together.
What if he said he was number one and two LOL. I would be thinking big when it comes to Lex, Anit-matter weapons, ultra-nationalist, EMP (knock a super power out of the equation off the bat). A team of ultra nationalist steal an EMP being developed a berkley (currently being built) is taken shipped to Kansas. Hooked to a weather balloon, taken 19 miles above the U.S. and used. Taking out the grid from sea to shinning sea, the military, the economy, and leaving the US to deal with that while some ultra-nationalist take over someone else. In any war I think the key is to keep the US out of it (where that good at war), maybe your main conflict could be a war between china and russia, over natural gas and oil fields along the boarder they share, a nuclear exchange ect. ect.
The only way for a war to be an actual world war would be if the "super powers" start fighting each other. Right now those are the U.S., China, and Russia (at least they have the military of a super power, economy and culture not so much). However the likelihood of these countries actually declaring war on each other is small. It comes down to allies, just like the other world wars. Look at North Korea for example: they are allied with China, and are officially still at war with South Korea (U.S. ally) as well as the United States. North Korea and Iran are the wild cards, however Iran doesn't have enough pull, support, or allies in the world stage to trigger something this big. If North Korea attacked South Korea the U.S. would be obligated to help (we have troops stationed there just in case) and China would be obligated to help North Korea. Both China and the United States would be stuck in a war neither of them wants (china depends on us for coal). If that happens we would have to look at what Russia would do. If they join with China that would be a world war unlike anything we have ever seen, with the UK, Canada, India, and other bigger nations having to get involved. It would be a mess. You could have Lex make it look like the North attacked, when they really didn't, and the rest would follow like dominoes. If you want to get interesting and a little less realistic, you could talk about Antarctica. Right now no one officially owns it (all though some countries think they have parts). If a precious resource was discovered the worlds governments would be at each others throats trying to have it. The natural resources found in Antarctica in real life are not worth the effort, so your would have to make something up (unobtainium? lol jk). Either way presents interesting story ideas.
Actually, another "superpower" is EU and that is under economic control of Germany. They are the strongest economy and basically, about most issues, it goes the way Germany wants. Just recently, Germany compromised a tiny bit on EU budget, in order for France and other more "socialist" countries to agree to approve it, otherwise there would be no EU budget, euro could collapse, the EU could collapse. Germany has been showing tendencies to want to completely control EU, and we all know what happened last time Germany wanted to control Europe. Because of the economic control of EU and a very strong influence in NATO, I think they (Germany or EU under Germany's control) have to be counted as a possible factor in this scenario.
Being Serbian i couldnt help but think we would be blamed for WWIII we were blamed for WWI and dont know really why but we were also some what blamed for WWII (having wars every 10 years probably didnt help our case), and according to some US magazine we are to blame for the apocalypse too! They based it on the Nostradamus prophesies that the events of 1999 (devils number upside down,EU vs Serbia war) will set the end of the world 13 years later, and that Serbs are to be blamed not the Mayans...
A short list: Religion Resources Nukes Terrorism Have's and Have Not's Since war is the most asinine thing in the world, each of those for the most part are stupid reasons to fight, but then people don't want to listen to each other or compromise. As Hemmingway said: The first panacea for a mismanaged nation is inflation of the currency; the second is war. Both bring a temporary prosperity; both bring a permanent ruin. But both are the refuge of political and economic opportunists. Ernest Hemingway Never think that war, no matter how necessary, nor how justified, is not a crime. Ernest Hemingway
I think you could consider the EU an economic superpower (even with recent euro-zone dept problems), but not so much a military one. Although their combined military strength is close to the United States, their military is not unified, and is fractured between the different members. Even though Germany does have a lot of control in the EU, they do not have a very big military (compared to the U.S. Russia, and China), and spend little money on it. Both France and the UK spend more money on their military and have more manpower then Germany. I think the day's of Germany being a major player in world wars is over. In my opinion the EU is too fractured and devised to be a major superpower in a World War 3 type scenario. There are too many different cultural identities to come together to fight for one-another. Russia, China, and the United States has a large national pride that can fuel the engines of war. I think the EU would break apart during a large scale war, with some countries on one side and some on the other, as well as some staying out of it.
Not to mention all of Nato officers are trained in Missouri, most Nato operation require US logistical support, NATO secure comms are American Secure comms.
I would definitely agree with this - an escalating financial crisis, perhaps worsened by the acts of individuals, an increase in the disparity of people's wealth, the people rising up...
I'm going to go with water, some country decides to damn the fresh water supply of another, I believe Turkey really have this fear. A naughty country disabling satellites in space, disabling all communications, arms, banking, from around the world.
One thing that could cause a massive war would be if China tried to cash in on America's debt. That would escalate to nuclear warfare with nations caught between that would probably take sides. I mean, if China tried to cash in America they most definitly would try to do it to other countries. Superman would be the only thing to stop it before great losses are made.
You could do a kind of "civil war" or mutiny thing. If people don't agree with what the government's on a very large scale, than the public could revolt against the government. If it's the US government you'd have them fighting with, you could have other countries pick sides. So maybe Canada is siding with the public, but Australia is siding with the US government? Could turn into a free-for-all full scale war with peopl joining whatever side they believe in. Then maybe the government could try to draft people to the army, but the people are refusing?
How about Lex taking control of the internet, spreading false news stories etc and blocking denials/genuine stories.
I would have to agree about North Korea... It wouldn't be hard to set them off. Perhaps giving North Korea access to a major supply of oil from the Middle East.
This is funny. You don't think fake news is the current standard mainstream news content now? Perhaps you meant a specific false story as opposed to the run of the mill every day false story? I don't know much about Superman plots. The three biggest areas of unrest currently are religious ideology (Christianity/Islam), political ideology (Ayn Rand Libertarianism vs Progressive balance of capitalism and the government's role in the public good), and the significantly unbalanced concentration of wealth at the top. The pending triggers would be water wars, (not oil, we'll have alternative energy as the cost of oil goes up) and global climate catastrophes. That's my opinion anyway.
I was thinking that Luthor could arrange for one his super-villains to blow up the Dome of the Rock in Jerusalem which would set off the entire Muslim world and frame Israel or America for it.
Ok I got one. What if archeologists discover ancient relics that give definitive prove that Jews are not the Chosen tribe, and that evidence sends shockwaves of disbelief and betrayal throughout the Christian faith disproving the coming of the Rapture, and pitting the State of Israel against the Christian and Arab world; The classic David vs. Goliath scenario.
Right now I'm thinking: North Korea vs. South Korea and US. (But then again NK is pretty much pariah, so who would back them up? Potentially China and Russia, but really, I doubt that). Israel is invaded by numerous Arab countries and the West intervenes.
The obvious ones relate to nuclear warfare, or oil production. But like other posters have suggested, things like Lex invading the internet would work too. It would much more clever, mysterious and potential terrifying as well, which could be very effective indeed.
If you're thinking locally, a war on the Earth by the people of Earth, a world war three would require a large portion of people to be opposed to another large portion, i.e., in WWII there was the Allies vs the Axis powers. The causes in that war were: opposing ideologies of Fascism vs non-Fascists (but not completely), the acquisition of resources - Germany (and others) wanted/needed more land, and the acquisition of power within the respective countries (using fear to gain power is as old as dirt - Caesar did it). So, what I'm saying is: don't look to any one reason. Unless we are invaded by ET... Also imo, a US vs North Korea sparking a world war three isn't a likely scenario in our current political climate, for reasons that I took the time to write, but then deleted, realizing it's too political. If you choose the religious route (which sounds like it would be a can of worms), just remember that nearly every war has ulterior motives.
