I agree that people here are uncritically regurgitating propaganda but of course liberals are also guilty of this.

fair enough, i mean everybody is, although i think the ideology of liberalism is uniquely suited to it since it's a sort of meta ideology in it's own right. When appropriately used it should be pretty hard to get mislead, but of course, people aren't very smart and use things incorrectly all the time, so that doesn't really help much. But there's an argument to be made for it over things like conservatism and communism where those tend to be a lot more rampant by design.

Most sources of information are controlled by or at minimum influenced by various powerful forces in society, each with their own interests.

this is true, but there is also an equally big, if not larger trap you can fall into with alternative media, just look at the republican party right now. It's on par with the nazi propaganda machine in terms of how well it functions.

I guess it is a little more surprising to see people absorbing propaganda from hostile foreign nations than from their own.

this one is definitely the most baffling to me. The fact that US citizens will unironically consume sources like RT for actual news is wild.

But another part of me thinks I’m not being critical enough of the idea of nationalism which is a harmful and largely fictional concept.

I would argue that there is an inherently negative value in nationalism, aside from support of that governing body itself, and an innate positive value in something like patriotism instead.