I think that your criticism of the article, while technically correct, is misguided and guilty of missing the point. Yes I agree that it can be conceived as a possibility that a State entity could be involved in perpetual war beyond its borders while at the same time being a refuge of wealth and security and progress towards more social justice for those within its borders. So yes, I agree that " "You can’t have an effective progressive movement in the United States that doesn’t include working for peace." is theoretically an overstatement of what can be proven about the future and so cannot be accurately stated as an absolute truth. But, that is a microscopically small, and therefore an insignificant as well as irrelevant, nit to pick, IMO.

I wish I was wrong but I don't see the peace movement having anything more than a marginal effect.

Again I agree so long as the movement remains a marginal concern of the voters, but if constant war only brings out the most benign result that can be expected, which is the eventual bankruptcy of our economy, then social justice is going to take many steps backward. That is another “absolute statement” that predicts the future and so cannot be considered to be infallibly, inarguably, correct but which, again IMO, only a fool with no knowledge of history would dispute. [Ask contemporary Venezuelans as just one of many examples currently available. Even though it hasn’t been war that has bankrupted their country it is their economic crisis that is leading to repressive governance]

Yet we can still have an effective progressive movement even if we have little effect in working for peace.

I strongly disagree and add that the only reason to work for a progressive movement is the demands of conscience. We have supposedly realised in the U.S.A. that internally dividing our citizens into defined groups and allowing policies that favor one group over the others is wrong. If that realization creates moral imperatives then, IMO, those imperatives extend beyond our borders. Virtue signalling about what is right versus wrong here at home while supporting actions which destroy entire countries makes irony the sick joke punchline of faux morality.