If the Major took the time to find the notes his group wrote and give them to him instead of selling them to Owl as well as surviving the Pripyat evacuation, he'll join the Ukrainian government as head consultant of their newly created Zone Study Institute.
Even if he suffers a temporary setback on his way there. Radiation, anomalies, mutants, psy-emitters, even being sandwiched between two factions hellbent on stopping him all the while he is being pursued by a mercenary is not enough to prevent him from accomplishing his goals.
From then on, the story sees him wiping out several groups of bandits (including the entirety of Borov's 30-man gang in the Dark Valley), exploring a series of increasingly dangerous labs, decimating at least two platoons of mercenaries, surviving an emission with nothing but a fainting spell, pacifying the zombie-infested Lake Yantar so it's inhabitable outside the mobile science bunker, surviving an explosive booby trap, going toe to toe with the Ukrainian Spetsnaz, chewing through so much of the extremely resilient Monolith faction that very little of it is left by the time Degtyarev fights them, opening the path to the previously inaccessible Pripyat by shutting down the legendary Brain Scorcher, infiltrating the Chernobyl Power Plant and slaughtering the C-Consciousness, controller of Monolith and, essentially, the Zone itself. Despite this, his first big mission is to infiltrate a heavily fortified military base and steal some classified documents, which he succeeds at with flying colors (either by sneaking in at night or going in guns blazing). He wakes up with amnesia and nothing but the clothes on his back after a truck crash, which essentially makes him a day one rookie with no stalking experience. He later appears as an NPC in Call of Pripyat.
And I guess I should be thankful for that".Originally the antagonist of Clear Sky, he is the Protagonist of Shadow of Chernobyl, who has Identity Amnesia after a lorry crash at the beginning of the game, waking up with only his PDA, which has the orders 'Kill The Strelok' written on it. "I don't know whether I was right or wrong, I guess I'll never know.