[Rainbow Six]

We've spent quite a bit of time discussing how to "neutralise" the United States...this is how I see events unfolding in relation to the proposed timeline...some of it from the timeline already posed by Raellus, some not, so in chronological order...

2025
a)Ongoing tensions in SE Asia, including armed clashes between the PRC and Vietnam. These develop into a full scale War which is over by sometime in 2026 (this serves to give the PRC leadership an opportunity to see how their forces perform in combat).

2027
b) North Korea launches an invasion of South Korea. Various nations, most notably the United States, send military forces to assist South Korea under the auspices of the United Nations

c) China takes advantage of the situation by attacking Taiwan as part of a long planned invasion. The US commits more forces

d) The Russians make their move into the Baltics, calculating that with the US committed in two different (but linked) theatres in the Pacific and the European members of NATO in disarray following the expulsion of some members from the European Union, NATO will not go to War to defend the Baltics. The Russians specifically do not attack Poland as they believe that will trigger a NATO response. The Russian leadership have miscalculated however, and NATO - or at least some members - does respond, leading to the War in Europe. US forces in Europe consist of one heavy Division based in Poland, with a second heavy Division quickly flown in and equipped from POMCUS sites in Poland.

e) The US Government calls up the National Guard and reserves, who begin to deploy to Europe and Asia to reinforce the Regular troops already deployed.

Whether c comes before d or d comes before c probably needs to be finalised.

Date To Be Confirmed
f) The War goes nuclear. Location of first use of nuclear weapons to be confirmed.

g)This leads to a gradual escalation in the same way as the original T2K timeline, i.e. with a phased period of time between first use and the launch of strategic weapons at the United States.

h)In the wake of the nuclear exchanges trouble flares on the US / Mexican border. Increasingly violent clashes occur at several border crossings, culminating in a massacre of Mexican civilians at one border station; elsewhere several US Border Patrol officers are found dead on the American side. Their deaths were neither quick nor painless. Some suspect the involvement of Mexican drug cartels. With little to no diplomatic channels available to defuse the situation, the Mexican Government orders units of the Mexican Army to the border to protect Mexican civilians. However tensions continue to escalate. Mexican troops engage US forces and in a matter of days open warfare has broken out along the border. The Mexicans are facing an assortment of Army Reserves, Air Force and Navy personnel, Border Patrol, and police, supplemented by volunteer militia groups. Several weeks after crossing the border, the Mexicans receive welcome reinforcements when two Cuban ships arrive carrying Russian troops formerly based on Cuba.

I think it's important to note a couple of things.

Firstly, in my mind this is absolutely not a planned invasion, It's not part of some Chinese / Russian /Mexican grand alliance, it's a War that starts almost by accident - albeit possibly following some manoeuvring and manipulation by the cartels - when some Mexican troops get itchy trigger fingers. Once it's started it escalates quickly, in no small part because neither side has any effective high level command or control over the forces involved, and by the time that command and control is properly established the fighting has spread too far for either side to be able to stop it.

Secondly it takes place after the nuclear exchanges have taken place. Therefore, personally I don't think it's necessary to go to lengths to further destabilise the US - by now its already been attacked by nuclear weapons and most of its regular armed forces - and National Guard and Reserve - are deployed overseas in Europe or the Far East. So as sated, the Mexicans are facing an ad hoc mix of forces, very few of whom would be trained combat troops.

In my opinion that's enough to make a Mexican "invasion" of the south western United States plausible. So Targan, whilst I think the germ warfare scenario you've put forward is a perfectly valid one, like Raellus I'm wary of introducing bioweapons into the scenario. I also don't think using it as a mechanism intended purely to destabilise the US to make a foreign invasion more achievable is actually required. Reason I say that is because I think that in the scenario outlined above the US has already been weakened to the point that the scenario is plausible and a large scale bio attack - especially against the "homeland" and, by definition, aimed primarily at the civilian population, would run the risk of a disproportionate US nuclear response, which goes beyond the original T2K "limited" (I use the word relatively) nuclear exchange - you said who would they retaliate against, but I would counter that by saying that rational heads might not be prevailing following such an event, so they may retaliate against everyone that they thought responsible. Or they may have specific intelligence that identifies the culprit to a level that they are comfortable with. Or, as you said, there may be something in the pathogen that means its source can be identified.