Well, it offers a huge military advantage, so in the interests of waging war, it is very useful, if not necessary. But I think the most common use of it is pro

Well, it offers a huge military advantage, so in the interests of waging war, it is very useful, if not necessary. But I think the most common use of it is probably the fact that politics is a game of hypocrisy, and you can't play unfairly if you don't get to keep secrets.