Arma 2: Harvest Red | Setting Sail
"Despite the Russian withdrawal we suffered massive losses. There's no hope now. It's time to leave."
Requirements:
Extradite Lopotev.
CDF Base is destroyed.
You'll start north of Elektozadodsk in a Ural with your team, along with CDF and NAPA personnel. This is a fight you can't win now, escape and live to fight another day.
Also: not sure if killing Lopotev prevents this ending from being achieved, I used the campaign cheat to access the mission.