Just to keep the record straight, let's remember your original question, under the heading "Economic Nationalism":
"U.S. economic nationalism equals U.S. imperialism? Any argument?"
I take nationalism to be connote a popular ideology, or perhaps a deliberate policy, whereas imperialism is a system. But obviously an ideology can lend legitimacy to a system, and the system can fuel an ideology. Fine.
One variation of nationalist ideology is the typical jingoist litany, in which case your equation is simple, obvious, and uninteresting.
Another variation is one that could be inferred from the Seattle events and the posture of U.S. organized labor. I took this to be the one to which you referred, but by your post my inference could be wrong. At whom was your question aimed?
As for imperialism, I'll note that for me, presently, for all practical purposes, "imperialism" a) exists; and b) equals "U.S. imperialism" So that's not at issue either.
What is in question is what I see as invidious links between U.S. labor's position on trade and imperialism. As examples of economic nationalism, I cited agitation against runaway shops, and against competitive imports. You seem to reject both as manifestations of imperialism, on which we agree, and as nationalistic (in the sense of imperialism?) as well. If there is no rap on labor as falling prey to nationalism, then we have no argument except over semantics.
As far as labels go, I would not call 'economic nationalism' an inappropriate one for the anti-globalization activity coming from labor and others. Evidently others here who oppose such activity, or tendencies within it, would not disagree.
Cheers, mbs