I agree with your gripe about the cost, West Coast. There are too many free-riders on this side of the Pond. Both Trump and Obama made it very clear that the US expects European states to pay their way.
I'm afraid though that a unified Euro force would never happen. There is never, at least in the lifetime of most of us on this forum, going to be a United States of Europe. There are big cultural differences in the way the USA and any USE were/would be formed. You could do it; I don't think we can...and anyway it would be without us now.