why are england ireland and austia not member of eu? (they join in 70) and finland and sweden (join in the 80)???
Let the speculation begin...
Oh wait, I know the answer. Fire_Unionist is right.
For the next version, there will be no EU per say, but at the beginning of the scenario, all the members of the EU which also are NATO members will be allied.
The UK is in a seperate alliance with USA since they are an US puppet.

Another reason is that they like starting wars that other european countries won't participate in. At least not with a level troops that can modeled in MDS2. (Brigade)
When WW3 starts, they will all join together in a alliance named NATO. This alliance does not exist at the start, but is modeled with guaranties of independence and military access. Sweden, Finland and Austria are going to be neutral all the time unless they are attacked. Non-EU NATO members such as Norway will join NATO and thus be in WW3. Turkey will most likely suffer an revolution and become either part of Shanghai Pact or ECON. US allies in Asia will also join NATO when WW3 begins.
The 3 major alliances are:
- NATO
- Shanghai Pact
- ECON (Middle Eastern alliance led by Iran)