As far as EU2, I dunno as I've not played it, but in EU 1, if you're in a war and lose all of your military and all of your provinces - even if not all to the same enemy - they can force a peace treaty of very harsh terms against you that you don't even get asked yes or no on. (I once had this happen as Ireland, and England took 2 provinces and some cash, and one of their allies also got a province of mine.) The accept/decline dialogue never came up.
And BTW, the white peace after 3 years only happens if there is no interaction between any forces, and no occupied territories.
And BTW, the white peace after 3 years only happens if there is no interaction between any forces, and no occupied territories.