This was originally a reply to oyster, but expanded a little as I went.
I was going to say that gender identity is a huge part of this, I think.
I mean we live in first world countries which in a way give many opportunities to be a part of something bigger...
That's the problem, though, as they're so big that they're abstractions.
Think about it this way. I grew up in the southeastern US. If I had been born even 60 years previously, I would've been on a farm. I would've learned to hunt by the time I was 10, I would've worked the fields, etc. I would've had real responsibility that mattered in a way I could see. I would see the crop fields, I could see my family eating what I helped provide, even from a very young age. It's all very tangible, and it'd be easy to to connect my own efforts with real results. I may not have been able to easily talk to people on the other side of the world, but I'd know everyone in my county, even if they lived miles away.
But now? Maybe I get to do a DIY project or something. Ever since I moved out of my dad's house at 18, I've never really known my neighbors. My ability to provide for my family centers on a job, and God help me if I lose that, because my identity goes with it. The highest rates of suicide in the United States are middle-aged white men in the mid-West, at 44 per 100,000.
I'm about as comfortable, educated, and liberal as they come, but I continue to struggle with this to this day. I was born in the early '80s, and while my mom is as liberated as could be, there was still the more traditional underlying dynamics in my parents' relationship, to say nothing of my grandparents'. So I was still kind of raised with this idea of being the provider, even though that dynamic doesn't really exist in our society beyond some echos. My wife has said she'd love to be a stay-at-home mom, but economically that's not in the cards right now.
Women's Liberation or Feminism or whatever was great, and as we've seen still has some work to do. Unfortunately, we can't have a corresponding conversation about what men should do too--Feminists too often get defensive, and Men's Rights Activists have utterly failed to come up with a reasonable alternative. These guys seem to have a lot of that going on, with militarism being the stand-in for masculinity. I mean, it's a little hard to take seriously with the code names and the names of the groups themselves. It really reads like an attempt to regain some ego. I notice too how (and I've seen this elsewhere) they talk about themselves as those who know what's really going on, and how they're the beginnings of some new elite. There's also the sheepdog nonsense, after a letter that's been circulating around the internet for awhile.
What's kind of sad about this is how easily taken advantage of these guys are. The firearms industry (and those that make associated stuff) makes a killing on this mindset. The prices for guns and ammunition go through the roof every time a mass shooting happens, because people assume the ban is coming. After Sandy Hook, you couldn't find an AR-15 if you wanted to.
And this mindset can have real consequences. If you watch the video of when LaVoy Finicum (part of the armed occupation of that wildlife refuge in Oregon) was shot by police, you can see the battle in his head. This was a guy who had written a book that culminates with the narrator quick-drawing on and killing corrupt federal agents (another review of sorts is here). Watching the video with this context, and you can almost see his thoughts as he struggles with the fact that his moment of glory has finally come but that reality is far different. He paid for this conflict with his life.
This line from the article sums it up nicely:
It's as if many militia leaders know they are dealing with a pool of volatile white men, some of whom are convinced that society has screwed them and are at risk of exploding. For some, like Doc, the militia seems to rein them in by giving them a sense of purpose.