There's also a huge cost for taking action about this especially in the US. You can easily get thrown out of school, have your career destroyed or be deported.
This. There are entire groups dedicated to rooting out any sign of deviation from per-authorized storyline and verbiage. It is particularly striking given that US considers itself 'free speech' bastion.
This is mostly a US thing. Netanyahu and Putin are two war criminals according to International Court of Justice. Although Trump threatened the ICJ, this doesn't change that basic fact.
Already in 2002 US passed the "American Service-Members' Protection Act" that allows USA to deploy military to prevent U.S. or allied officials and military personnel from being prosecuted or detained by the ICC.
It passed via bypartisan vote well in time before US launched the illegal invasion of Iraq in which it committed various war crimes.