Aztlan shares a border with the PCC and CAS. To reach CFS, Aztlan has to go through (or around) Pueblo Corporate Council lands. If they try to punch through at the narrow strip, Aztlan has to then defend its entire border. PCC is not going to readily give up its only port city (Los Angeles) as it is otherwise landlocked. Both the PCC as well as the CAS and Ghostwalker up in Denver would LOVE to take a shot at pushing the border back to the Rio Grande.
Ok, so the Azzies are already using the dissadent Ute in the PCC to cause trouble there. You also have the Treaty of Denver renegotiations, which on the surface are unlikely to give the Azzies much, but they could covertly support someone in return for their support in their expansion. I don't think the Japanese are going to like being that close to the Azzies and Horizon is no friend either...
So you have to keep them busy, buy their support or.... try something completely different...
Indonesia once did something that really could work here... They invaded a nation to restore peace (actually I think is not that uncommon...). If you could have a Ute uprising, one large enough that it became difficult to contain, the Azzies might be able to cast themselves as peacekeepers, restoring order in a failed nation (or at least the bits that failed...).
Key factors in anthing are people and money. If you could bankrupt the PCC (are at least cause them financial distress) via a third party... say technomancers targeting Horizon, maybe even set the Denver Data Haven folks against Horizon (the Denver Data Haven is in PCC territory and has some sort of relationship with the PCC), maybe also use the Ute to target this whole 'shares' thing that the PCC has, and then arm an uprising terrorist faction.... maybe something like a scenario from '24' with magic thrown in.... and bang, PCC is in chaos on a number of fronts and then stage a massacre of peaceful Ute protestors (or similar) in the territory you want to 'free', have a peaceful rep of the protestors call for internation support... and send in your
paratroopers peacekeepers.
Now, what to do with LA and San Fran? Maybe the peacekeeping mission in in LA and leave the Japcorps along in San Fran. Two much hassle to fight a second front against more megacorps. (They would likely already be in a shadowwar with Horizon regardless...).
Probably halt near Hestiby's territory, don't want to provoke the Dragon.
May need to blackmail a high level CAS rep, or assassinate their president, or something, to keep them busy and out of the picture, otherwise they may take Azzie peacekeepers as an agressive move and may accidently trigger a border disputer/war.
How to involve runners?
Break it into a number of Azzie-backed runs (the sort where the Mr Johnson is never the same and none of them speak with a mexican accent... but over the course of the campaign, have trid reports handed out which clearly show the Azzies taking advantage of each mission's outcome.
Start with a Bang, then go small, and then have regular Bangs until you build up the momentum... and then have the runners change sides!
I suggest.... hmmm... and this is just brainstorming... I would also suggest running the Twilight Horizon stuff at the same time, just because it would explain whats keeping Horizon so distracted....
Mission One
An assisnation of a Treaty of Denver deligate. Perhaps the CAS rep, and frame a Ute dissadent. This is important, as CAS and PCC are actually fairly tight at the moment, what with the common enemy, the Azzies. But if you can cause some tension here and start the whole Ute uprising theme, then hehehehe..... and its a heck of a first mission for a campaign.
Mission Two
Denvers a bit hot now, so lets go elsewhere... Maybe a prison break? A Ute leader, arrested for political crimes, is being transfered for questioning (re: recent assination). Time to break him loose, get him to his allies and hand over a sealed package....
Mission Three
.... I could go on... maybe in a later post. Its an interesting campaign idea.
Good Luck!