How can I balance the child's rights with the safety and security of the children around them?

The child's rights and the safety and security of the surrounding children aren't an either/or that makes someone endure. First understand why the behavior happens (the triggers) and reduce it with support suited to the child. At the same time, if a surrounding child is frightened, receive that feeling too and protect them. In situations with danger, prioritize safety, and protect both by having an adult step in or arranging the environment. Aim for "both," not "either," and share concrete measures with the preschool/school.