what does the Napa stand for?

The Red Star movement Obviusly must be communist more or less decending from the Soviet union and since the Americans is supporting the CDF they must be pro western democrazy but what about the Napa?

national party, That would mean strong nationalists but what rule do they wish for?
why are they on their own? if theyre communist they could join the red star and if theyre democratic they could join the CDF, i know the world is not black and white as in the cold war but still.

what are your thoughts about this?

I think NAPA is an allusion to most small nationalist movements that form as a resistance group to occupying forces.

I also think your questions pretty much answer themselves if you look deeper.

Which side are they on?

Can they be trusted?

I tend to think the answer is they pretty much fight for themselves - possibly assisting one side or the other as an effort to gain more than they give.

I would say that NAPA could be something near a "neo-fascist" party or "nacionalist" party as you already said in your post.
A quite similar group (in this case political party) arose in Russia during the 90's lead by a guy called Vladimir Zhirinovsky (but only in a political way, not in a armed group way). These groups are usually located in the far-right wing political spectrum (neo-fascist/nacionalist) and thus are usually considered to be not only "anti-communist" but also "anti-democrats" which makes them to be "anti-west" most of the times and in the case of ArmA2 a such group would definitly be a rival or even an enemy of "pro-west" factions like the CDF. I believe that NAPA in ArmA2 is modeled with such groups in mind.

That makes sense to me. its an interesting plot with 5 factions + civilians instead of the usual 3.