Really depends on the union, workplace, etc.. But there is definitely a kind of imperialist tendency baked into the Western economy, and that does emerge in labor organizing. For example, it would benefit a union of textile workers for the US to put tarrifs on say Bangladeshi textiles which would give a greater competitive advantage to US textile firms. So what's the problem here? Well Bangladesh will continue to produce Textiles, but the wealth from that production is split even thinner between the state, factory and workers. This would hurt the QOL of Bangladeshi textile workers. This creates a situation in which it appears to be advantageous to an American worker to look out for themselves, but of course that isn't exactly the case. The additional tarrifs don't really bring back production to the US or increase US wages, the US state pockets a larger share of Bangladeshi capital, and prices rise in the US anyway. This example is loosely remembered from John Smiths Imperialism in the 21st century. Really recommend the first chapter. (he has weird China takes tho).

Another example, unions in the US (likely) understand that a strong American state on a global scale (I.e. One which can push other countries around at will) benefits them in the long run. So they may be supportive of policies which help bolster that position instead of challenge it. Most brits were not happy about the whole fall of the British Empire, which is likely the best parallel for the dominance of the American state today (but in a slightly different way).

I made a throwaway post in the mega today after looking at a post in r/union, and tbh it was just a bunch of drivel about how Trump will weaken America and take pressure off of China. But like, it was pretty mask off.

While this book is old, has its problems (you can skip about half of the book tbh lol), and is a bit more of a tangent from this post, Reichs Mass Psychology of Fascism has some good bits on the psychology of imperialism embedded within the "middle" and working class. Even though it was written right at the point Hitler seized power, I think it still has explanatory power today tho even if I think some of its conclusions miss the mark. I forgive him though, he was a very early Marxist-Psychoanalysis guy.

All that said, unions are good. Organize your workplace, or if you are already unionized, get elected to important positions within it.

There are definitely strong contradictions between the interest of the working class of an Imperial core country and the global proletariat, but that shouldnt steer people in the core away from labor organizing. Just be aware of this and push back when you can. Even getting your union on a stronger anti-war position is helpful on a global scale. This isn't even to mention the contradictory interests within the unions as well, between a boomer class with cushy pensions (who helped decimated unionism in the Imperial core and are the biggest annoyance when organizing) and the younger workers who have limited protection/pension/benefits etc. For example, if your union owns real estate as part of its pension or invests in real estate investment firms, they are profiting from a mass inability (including workers they represent) to buy a house or pay less the half your income in rent. Explaining this to them generally falls on deaf boomer landlord ears tho. For them unionism remains an individualist affair, and if it is not based on collective power it can just be HR by a different name.

And none of this really touches the way in which social programs in the imeprial core are funded, which is a whole other bag of worms that the MMT people like to overlook.