North Atlantic Treaty Organization. My guess would be that it's because blue is a pretty color, and blue is the color of the ocean. "North Atlantic" in the title of NATO refers to the Atlantic Ocean, so that might be what it is.
Well, Israel is the only possible conclusion that could be reasonable, right? No other nation or group of people have ever used blue or light blue colours for anything. And in combination with white? It would absurd to suppose that combination could ever occur again in any of the... *checks list of flags by colour combination on wikipedia*... Nevermind.
Yeah, whatever. I think we can all relate to blue. Look at the sky. Go on. All of you. We can all see it. From every country, we can all recognise the sky and it is usually blue and white. From space, our planet looks blue and white because of our atmosphere and oceans. Blue is entirely inoffensive unlike some colours such as red (especially when people used to hate communism and bloodshed). Blue is probably universally seen as peaceful and calming among humans. There are many reasons why blue and white are a good choice and I guarantee it has nothing to do with a single small nation or a tiny religious group.