If and when a war does happen in our current situation (presumably if nothing much has changed from the status quo), it'll be because one of our allies or at least someone of power feels they've been alienated or are being unfairly exploited/taken advantage of. Or some ambitious faction is trying to usurp control over people.
And yes, look throughout history, you'll find that the overwhelming majority of all wars inevitably came down to/have been about a fight over resources, with a close second reason being about power. This is almost always what war has been about.
What's different now is that everything is at a standstill with tension in the air. Since everything is now stacked up, there are no sudden surprise upsets that can really happen. It'll be a gradual whittling away at the status quo until something gives way.
A third major reason, so distant yet so close is survival. Prosperity. Which implies a post-disaster situation.
I do think that in light of all that is going on, something else is going to happen. Natural disasters. Could be something waiting at an astronomical or cosmic level to strike us on Earth, or maybe it's something long overdue by hundreds of years from Earth itself like the "ring of fire". What is that? Talk to a geologist, it might scare the hell out of you. Or any number of other things that are classified as natural disaster. A post disaster struggle for survival and prosperity would be a plausible distinct possibility given these circumstances. Hell, it doesn't even have to be a bombardment from nature, it can be much subtler like drought and famine.
As-is from an economical point of view: Fixed land (arguably shrinking to some), and a growing population equals inevitable starvation. Famine happened long before technology got to be anywhere near as advanced as it is today. Imagine how much more nasty it'll be now.
I'm no green party activist, but even for a conservative leaning guy I have grown up largely around nature and lived in it. There is an appreciation there that I have of it. Call me a conservationist in this aspect. I can tell you now that another factor being damaged tainted uninhabitable land (for whatever reason) is something to indeed consider. I'm just telling things like I see them. There is also no completely safe area on earth from some form of natural disaster.
So if it is not any nation(s) causing ruckus, it'll be nature lashing out, then the subsequent vacuums of power amid devastation, and the vies for that power on top of everything else going on.
"I cant see S***! --YOU GO TO HELL!" --Tourettes guy