I have not finished the game yet, but I must have missed something because I don't understand the FIB's motivation for getting Michael and the gang to mess with the IAA. the first mission you have with Dave he talks about an informant that will expose the corruption within the FIB so you go in to the morgue to check if he is actually dead or not.Then you kidnap the guy and torture him, I have no idea why you kidnap him, how he has information on the FIB or why you have to kill the guy he gives up during the interrogation. Now I am getting towards the end of the game and the FIB guys keep talking about funding that they need and now I have to steal nerve gas but I have no idea why and it's really confusing me.

Sorry if I am coming across as stupid, I just feel like I have missed some vital piece of information that will make it all make sense, or I am just not at the point in the game where it has been revealed yet.

Any help understanding would be appreciated.

You're not getting towards the end. I just did the mission involving the nerve gas and it feels like I still have a long way to go.

Just finished the game, erm from what I remember they needed to torture the guy to figure out if anyone else out there could tell the IAA info about the FIB. After that Im sure youve done some previous stuff like steal money for the FIB and I think they use that as leverage on you to help them with the nerve gas mission.

@optix12: "nerve gas" mission. Hehe...

they found out someone was making bad perfume!!!! it was actually cat piss! makes people angry at fIB agents...

The FIB has a rivalry with the IAA; primarily for funding opportunities against the war on crime. The IAA have been advantageous at this time.

Both want to find intelligence regarding Mr. K's alleged terrorism involvement in Los Santos; Despite the vagueness of Mr. K's involvement, both want to make an excuse for funds. In the end, the FIB succeeds.

According to Steve Haines, the IAA allegedly want to use the nerve toxin, with collaboration from a terrorist, to be unleashed with the goal of more funding for the Agency.

Instead of doing it purely themselves, especially Dave Norton and Haines, in risk of their careers in addition to funding, they use the crew to cover the tracks.

@thephantomnaut: Thank you very much, you answered all my questions and it makes sense now.