When I was in college, I took an elective course called “Introduction to Military Intelligence”. It was one of the best courses I took during my four years in college. The teacher was a retired Army Major, and a very nice guy. (Our first day, he made the old joke about military intelligence being an oxymoron.)
One of the big things I remember him saying was that “the bad guys always have a tactical advantage”. I’d never thought about it before, but it’s true, and it’s something counter-terrorism and intelligence officers have to contend with.
Bad guys are people who attack other people. Good guys are just minding their own business, not looking to hurt anyone. That’s one of the things that differentiates good from bad. This means, among other things, that the bad guys know when they are going to attack and how, and so always have the element of surprise on their side. The good guys are forced to be reactive and defensive, which is a tactically bad position to be in.
Now, there are lots of quibbles or counter-arguments you can make about this, as well as arguments over what constitutes a true “attack” (e.g. “weren’t the good guys ‘attacking’ at the invasion of Normandy?”) The larger point, though, still holds–bad guys are usually on the attack, and as such have an advantage.
So, what to do about it?
The solution most good guy nations came up with is to have people on stand-by, watching for and guarding against attacks by bad guys. This works pretty well, but they are still operating at a disadvantage because they usually don’t have first-strike capability.
It’s also important to note the difference between “tactical” and “strategic”. Tactical stuff is on a smaller scale, meaning one battle or one individual action. Strategic is a longer-term, big-picture thing. So, it’s possible to be at a tactical disadvantage but a strategic advantage, and vice-versa.