If you were, for example, a foreign power interested in either decimating or controlling the US, one obvious point of vulnerability would be simple: convince the American people that ‘diseases are just a psy-op’.

This would allow you to decimate the population without war. You can get them to kill each other simply by asserting that ‘there are no diseases’. Additionally, you can assert that, for example, a ‘measles outbreak’ is ‘just propaganda by big pharma’, etc.

The American public (in general, at the cohort level) is too poorly educated to evaluate any kind of claim in their own language, so, effectively, you can simply float claims that get them to obliterate themselves and each other… all day long, at a cost of pennies on the dollar. The way this works is simple, you take some conjecture or assertion that has a small degree of truth, i.e. Big Pharma is a conspiracy (not entirely untrue), and amplify it to produce a single-valued information weapon.

I can imagine a near-future where we hear things like ‘food doesn’t nourish you’, and ‘you don’t need oxygen to breathe’.