I completely agree with you: collaboration is no crime in science. Obviously, we will both be downvoted to invisibility, because this site's users are fervent nationalists, not scientists.
Faculty are required to report outside jobs, see: https://provost.harvard.edu/statement-outside-activities-hol...
Do you know when you accept big grant you also must follow similar rules?
Yes, you can collaborate in science, but you do not live in a vacuum, scientists also need to follow the rules of a society.
If the goal is for science, there shouldn't be restriction on working with other country in order to accept grant.