>>717885668
>>717886175
It's a whole big gobbledygook of retcons. In the OG timeline, Leon went with Krauser to South America to take down a drug lord who, surprise, was using BOWs from Umbrella before they tanked. Krauser was already jealous of Leon when then showed up and after the mission was over and Krauser critically injured his arm, that jealousy festered into betrayal. He reached out to The Organization, now being run by Wesker, to seek out a way to gain power which was why he was planted into Los Illuminados.
In the Remake timeline, Leon never went to South America. Krauser was there with his own team, to take part in Operation Javier. The mission was an especially cruel affair that would've embarrassed the US if word got out, so the participants were killed off when they tried to get a ride home. Except they missed Krauser, who became enraged with the US after the fact. Unlike OG, Remake Krauser went directly to Saddler and Los Illuminados looking for power to spite the US.