Using branching logic, in the survey flow you can branch people that indicate they are from X country from a drop down list to a version of the question that requires a response whereas all other participants will be branched to a version of the same question that does require it. This will create two different data points for the same question (e.g., question 1 for participants from X country AND question 1 for participants NOT from X country), but can easily be merged into one in whatever statistical package you use afterwards.

https://community.qualtrics.com/XMcommunity/discussion/19602/force-required-response-based-on-embedded-dataYou can't make a question required with JS. The best you can do with JS is disable the Next button on that page until the question is answered.