This question will resolve as Yes if, at any time between January 14, 2024 (day of creation of the question) and January 1, 2028, there is a military conflict involving countries representing in totality at least 30% of world GDP in PPP or 50% of world population in any month in which the conflict is ongoing.
Thanks to @Jgalt for inspiration of operationalization. Suggestions of refinements are welcome.
Some relevant info and thoughts:
Market on Taiwan invasion: https://manifold.markets/MarlonK/will-china-attempt-to-invade-taiwan
Noahpinion on the US capabilities (https://www.noahpinion.blog/p/were-not-ready-for-the-big-one) and on why China may want to shoot US bases if they invade (https://www.noahpinion.blog/p/why-i-think-an-invasion-of-taiwan)
Some explainations on why the US & UK have decided to start shooting the Houthis in Yemen (https://asiatimes.com/2024/01/why-biden-finally-attacked-the-houthis/)