International Federation was an international organization made up of all the countries in the world, with peacekeeping being just one of its functions.
When the US proposed to kick Luo Yue out of Sai Na by force, they didn't expect that the International Federation wouldn't completely pass their proposal. Of the five greatest countries, China simply passed on voting, but Russia actually voted contra any military action against Luo Yue.
As long as there was one vote contra, the proposal couldn't be passed. Like that, the US wouldn't be able to send troops to Sai Na blatantly.
Russia had only gotten some weapon deals from Luo Yue, though. Were they going to get on the US's bad side for a few hundred million dollars? It wasn't the Cold War period anymore, there was no need to get on the US's bad side for a mere Luo Yue who only had 200.000 inhabitants.