In a democracy the government gives students the opportunity of giving information of multiple sources. That is why in Germany we have many self research tasks for history, politics and other social related academic subjects. For science academic subjects we do it too, but more rarely.

The reason why you think “Schools have always been propaganda machines” is that the USA was never a real democracy. It is a Empire with 2 big oligarchy factions: Democratic Party and Republican Party. Because of First-past-the-post voting and the Electoral College it is easy to bribe/threat a small size of people to cheat the vote outcome. Also because they want to be votes again they just go with the popular parties again thus USA is a 2 party system. The Democratic Socialists party and Green Party do exist in the USA but they have no power, so some work the Democratic Party.

Oligarchs stay rich by staying in power. They make the poor even more poor so they do not have time or money to even go to demonstrate. They simply want the majority to stay dumb even at the cost of the world which is going to burn because of climate change.

The USA made sure to fix these issues in Germany after the Nazi regime’s end. But they did not for themselfs.

USA has subject states:

quasi-protectorates:
🇫🇲 Federated States of Micronesia
🇲🇭 Marshall Islands
🇵🇼 Palau

2003–2011 U.S. Occupation and Direct Control of Iraq: Today it may still is under the hood with CIA’s control. The CIA is very able to install vassals into another country.

NATO: Just like any other Empire. It has military bases all over the world. While it is not or mostly not occupation, it is still has power with the threat of suddenly send the army home and leaving the land unprotected from other empires/kingdoms/dictatorial regimes.