That is any+singular noun or plural noun? When to plus singular noun and when to plus plural noun?

And, can I say "This is nowhere more true than in the worldwide cooperation to improve the environment and to prevent some global violence."? I feel that this sentence is incorrect but I do not how to modify it. In this sentence, I want to emphasize that the worldwide cooperation can support my opinion and therefore I use "this is nowhere more true than" because I learn this phrase from this sentence: “This is nowhere more true than on the question of fantasy and reality.” However, in Microsoft Word, both "true" are advised to be substituted. I do not know the reason.
Perhaps Microsoft considers "true" an absolute. That is, a thing is either true or false. One thing can't be more true than another.

But in common practice, your sentences are common, natural, and "correct" in my opinion.

Any student who is late will be expelled.
Any students who are late will be expelled.

Both work.

You could also say "All students who are late will be expelled."