As The Hill has started commenting, "If you are anti-establishment [anti-war, etc.] this will be coming for you."
The New York Times beat the Iraq war drums with false information and CNN/WaPo/other usual suspects regularly do the same thing.
The rebel group they're supporting regularly commits war crimes including beheading men accused of working for the Syrian government.
[1] https://www.motherjones.com/politics/2016/08/syria-al-qaeda-...
I'll give you The Nation though, they seem to be anti-interventionism.
To actually find anti-war sentiments, you have to go to the small independent media.
Depends on the topic. Ask them about mass immigration, and they'll be falling over each-other to tell you how great it is, while many European countries with much more limited immigration also have many policies considered left-wing in the US, such as state-funded universities and healthcare, strong social safety net, shorter prison sentences and better environmental and consumer protections.
Or look at Thailand, where they have universal healthcare, but "amnesty" for illegal immigrants means they can leave without being punished: https://www.malaysiakini.com/news/10744
