Depends on what you mean by “vulnerable” and “impoverished”. If you mean actually in poverty, the US Federal poverty line in 2025 was an annual income of $15650 for individuals, $21150 if you’re in a household family with two children. However, if you look at the below infographic:
The vast majority of US military recruits are well above the poverty line. Even if you could extrapolate most of the 19% of recruits who fall beneath the annual income of $41691 as being at or close to poverty line, that still puts the remaining 81% of recruits in a broadly middle/ upper-middle class income bracket.
Just for reference, the average median income (that’s the 50th percentile of all income earners, not the average which tends to be skewed by the upper class) in the US was only $43222 in 2023. That means the majority of US military recruits came from a household that was already earning more than 50% of the US population.
So by any of these metrics, you cannot consider most US military recruits to be impoverished.
Additionally, the racial and ethnic demographics of the military, especially in the higher ranks, is disproportionately White by a huge margin. I think it is reasonable to say that these majorly White recruits are nowhere near as vulnerable to discrimination or poverty as someone who has a non-White background, such as a black person whose family descended from slavery, or a Hispanic who migrated from a poor Hispanic country that could very well be deported by ICE any day now.
What can we ascertain from these facts then? That most people that join the US military are White, middle class individuals who are very likely joining not because they are desperate to leave poverty, but because they like the idea of being a stormtrooper of the empire whose propaganda they willingly ate up. There are far more Graham Platners than Mike Prysners in the US military.
On your other statements about purges and pragmatism, it is ironic that you say purges lead to counter-revolutionary outcomes when purges are what prevented the USSR from being completely destroyed from the inside during WW2 (see the number of Nazi collaborators in the occupied Baltic and Ukrainian territories), and is why the PRC and the DPRK still exist today.
As a non-American communist, I fail to see how it is pragmatic to try and defend the jackboots of the American Empire who are willingly carrying out war crimes and imperialist atrocities while completely ignoring all the actually impoverished, brown people they are currently murdering in the Middle East.
If empathy is ‘pragmatic’ as you claim, then I will say it is far more pragmatic to empathize the victims of the empire and materially support them to bring them to our cause, than the stormtroopers who carry out the orders of the Empire without question. It is like saying we should ‘pragmatically’ empathize IDF soldiers who are genociding Palestinians because they are all conscripts who came from all socioeconomic backgrounds and maybeeee 1% will defect if we just keep saying Free Palestine.