How to write a strong villain who isn't really present?
I've been working on a quite large story for a while now, but going through my drafts I noticed one weakness: My villains are very underdeveloped / weakly characterized.
I'll try to generalize the question & example, to keep it relevant for other cases as well:
The main protagonists are not directly facing a villain, but are facing the results of the villain's actions (for example, war). So, they don't really face 'a villain' in the classic "hero vs evil overlord" sense, but instead face the situation and eventually the villain's troops or other minor odds.
This creates a large problem for the story: My protagonists face "faceless" soldiers but are never involved with the (charismatic? power hungry? misguided? manipulated?) leaders. Why would they want to? It would only cause more problems.
I tried to remedy this problem by giving the "other side" a voice, basically a protagonist that is involved in the bigger (background) conflict - but that just feels artificial (at least so far).
It's not that the protagonists are not heavily involved - the problem just is that with a certain command structure, it wouldn't make sense to involve a leader who should delegate, not run around and do it himself.
Example: (and my problems with it)
A large war between two faction breaks out.
Anna, for some reason, has the key (let's say, a magical artifact?) to make one side win over the other at the expense of her life. She doesn't want either side to win but can't leave the area either, so she tries to stay under the radar.
Both sides make it a priority to hunt Anna down - whoever finds her first and brings her back gains a huge advantage.
Now, I would say the leaders of the two factions do the only thing reasonable: they delegate the issue. Search parties, troops, etc. They maybe even give one high ranking member the responsibility to solve the problem.
And this is exactly my problem: there wouldn't be one person searching for Anna, there would be dozens, hundreds or more (depending on the resources available). She would never face the same 'hunter' twice if she keeps changing location, which would be the reasonable action.
The only way to have a reappearing presence would be to bring the leading person in the picture - but he would most likely just be sitting in some headquarters and organize his men. He would only come into play when Anna was captured, without any build up - and then his job would be done and he would be out of the picture again after delivering her.
What are good techniques to make an impersonal (background) conflicts more personal for the protagonists, or give the conflict a "face"?
Is it necessary / expected to force a person (that usually just sits behind a desk and wouldn't have a personal connection) directly into the scene, even if he would just delegate the issue and wait for results? (which isn't very exciting)