Why could they take such a flexible measure?

Here’s how to track Santa around the world, thanks to NORAD
https://edition.cnn.com/2022/12/24/us/norad-track-santa-trnd/index.html

It's interesting that the Continental Air Defense Command (CONAD) reacted the child's request kindly. If it happens in Japan, self-defence base won't make such a flexible reply, and will be treated as annoying phone call.