The market will resolve as YES if by the end of 2024 any country officially admits to sending any number of troops to Ukraine to act in any capacity on the Ukrainian side. This can include personnel directly participating in combat, as well as special forces, intelligence, instructors etc. The troops do not have to be in the Ukrainian chain of command, but they need to be deployed with Ukraine's consent.

The troops have to be on active military duty, volunteers don't count. They can be deployed either by some country's military directly, or as part of some international organization like NATO.

For the market to resolve to YES, both the deployment and the official statement about it have to happen by the end of 2024. The statement has to be explicit. A vague statement of intent followed by third-party reports about the troops is not enough.

I tried to verify that so far the conditions for this questions haven't been fulfilled. If I am wrong, please point me to the relevant news in the comment, and I will resolve the question.

I do not bet on my own questions.