In what way (O'Brien) is the domination desired by the "Party" different than the world domination desired by the Nazi's and the early communists?

's domination
is the perfection of what the Nazi's and early Communists sought.  In his world, O'Brien is able
to control people ( , eg.) to such an extent that external reality ceases to exist and is
replaced by whatever the powers in control wish to put in there.  This is symbolized by the 2 +
2 = 5 that Winston finally agrees to.  O'Brien didn't settle for Winston's agreeing...