If you don't kill the terrorist, he goes on to blow up a plane.
Being able to impact the world means being able to affect what other players can and can't do. ie, a loss of a bridge is a loss felt by all players, until the bridge is repaired by NPCs, which requires resources and NPC manpower, which in turn affects the world economy. The plane could be an actual game vehicle, that NPCs/PCs use to get about the world. The loss of a plane could mean a loss of life, and a small loss of mobility, meaning longer waiting times at airports. With that level of detail and impact. it sounds like we're adding a deep strategy layer to the game.
Not that deep. The latter aspect doesn't necessarily need to be visible to the player. If agents need to get around the world they'll have private transportation probably or it'll be a non-event most of the time.
I think having actions that impact the world and thus other players in some way is important in an RPG, which is what MMOs are supposed to be. Very few feel like what I'm used to RPGs feeling like. It's time to bring that back.
If the MMO has two (or more) factions, then players will be doing missions to try and hurt enemy factions, while trying to prevent damage to their own faction. What will devising those official missions will be the AI, for NPCs to carry out. But NPC's can also recruit player characters, allowing missions to be delegated to players.
If that's built-in, yes. The missions will be constructed by designers, not AI. There's no way AI can create missions of the type I'm thinking.
Also as players learn their way through the game world, and learn where their enemy's weak spots and strategically significant areas are, they'll be wanting to devise their own missions, and recruit other players to assist. It might be possible for players to write a mission profile and for other players to accept it like any other mission. If the strategy layer is complex enough, players will have the opportunity to be creative and ingenious, and that will surely be a source of exciting and meaningful missions for higher level players.
If players learn where enemies weak spots and significant areas are, the other side has done something wrong.
HQs should be able to be changed if necessary. One agency may be able to stage a raid against another, but I haven't decided if that'll be something doable right off the bat. It would be something that's possible as an add-on. The problem is making something like that doable without it devolving into the 75 man raid mentality or screwing up the game balance since actions like that are permanent. The HQ wouldn't just reset.
You must be suspicious of everybody, since they might be an undercover enemy agent, even in the assumed safety of your capital city. So you also have to be cautious about accepting their missions as they could well be harmful to your own faction, and if you suspect that a mission is like that, what would you do? If you call the agent out on it, they could simply rearrange their plans. If you raise alarm to your HQ, you should do so covertly and pretend to go along with the suspect mission so you can infiltrate it.
Missions wouldn't come from random people, they're assigned by the agency HQ, at least at first. It might be possible for agents to investigate "tips" from anonymous people at some point, but making those people enemy agents would be difficult.
Imagine how intense an undercover mission into an enemy city would be. Imagine how interesting missions could arise from complex tangles of bluffs and double bluffs. Imagine how rewarding it would be to con an enemy agent into doing something for you. Imagine how rewarding it would be to run a long con ~ going undercover and befriending an enemy player for several weeks, only to use them in a nefarious plan against their own faction at at a later date.
That's what I'm thinking. I'd love to see something like that, but studios just aren't thinking like that. They're all about making WoW clones and trying to cash in.