- Ocelot can't decide what team he is on. Russia or US.
Technically, Ocelot plays for his own team, which included Big Boss and Major Zero/Cipher until he just decided to take control of the Patriots himself (or was that Liquid's arm talking? I don't know).
Allow me to clarify.
Ocelot was 100% USA, that alliance then became more worldly with the concept of The Patriots, making the world whole again as envisioned by The Boss (although it was never brought up in the games, I assume at the point of the creation of The Patriots, Ocelot finds out that he is the son of The Boss and The Sorrow). Zero and BB disagreed over what that world was (equally as wrong as each other) and The Patriots split in half with Ocelot secretly siding with BB and EVA.
Metal Gear 1 and Metal Gear 2: Solid Snake happened, Zero captured BB's body and forced him to live a brain dead (locked away by nanomachines) cripple (the same thing that would await Solidus Snake in MGS4).
Ocelot and EVA hatched a two-part plan:
- Free Big Boss
- End The Patriots
As you saw at the end of MGS4, their plan worked
Liquid Snake did indeed take control of Ocelot at points during MGS2 when Solid Snake was near by ("You're the only one that can free me after all!"). This is the latent talking to the dead abilities of The Sorrow which Ocelot inherited but was never shown to use, realised were there or trained in. At some point between MGS2 and MGS4, with Solid Snake nowhere in sight, Ocelot had the arm removed and replaced with a cybernetic-prosthetic, stopping Liquid Snake there and then.
Every time you saw Liquid Ocelot in MGS4 was simply Ocelot pretending to be Liquid (nano-machines, hypnotherapy and auto-suggestion). The whole taking over and recreating The Patriots thing in MGS4 was part of the act. The two-part plan mentioned above never changed, if only slightly expanded upon because now Ocelot and EVA had the Patriots A.I. network to deal with as well.
Did Ocelot still have The Boss's world in mind at the end of the game? Maybe (again it's never officially stated that he knew about his parents even after all those years), it sure seems like her ideal world came to life with FOXALIVE. As for Ocelot, as soon as he completly dropped the act and became himself again the new "kill the living members of The Patriots" FOXDIE activated and killed him.