I did say capital spending, as opposed to operational expenses ("$5 million for the surprise drone attack next Tuesday at 0700"). If the public know you’re bombing Luxembourg, and there’s a $10 billion item for “Luxembourg bombing expenses”, that’s probably enough information for voters to make an informed decision.
But if there’s a $10 billion item for “none of your business”, that makes the idea of accountability into a joke. If an organisation has funding on that scale and you don’t know what it’s for at all, then you simply do not know what that organisation is doing. Mass embezzlement? Secret preparations to invade Canada? Illegal space weapons? Maybe it’s none of those things, but in any case, you don’t get a say in it.
Yes, a secret budget means (perhaps) that enemies also don’t know what you’re doing. That is indeed one of the minor advantages that tyrannical governments have over democratic ones. But even then, if the aim is to have less conflict, there is little point tricking enemies into underestimating your capabilities.
