In my view, there are two levels or elements to imperialism as we currently know it:
1) the hegemony of the US; and
2) imperialism as a world system of structured inequality, domination, dependency, and exploitation.
The excessive emphasis on the first seems to be what Doug is criticizing (using the "Empire thesis"). It's associated with a wide variety of populists and Marxists.
The emphasis on the second is associated with Lenin and a wide variety of Marxists. The "Empire Thesis" (as Doug explains it) seems a variation on this, since it can involve dispersed and polycentric power within the "core." After all, Lenin's original thesis (and that of Bukharin) involved competing imperial powers.
But the point is that the system isn't one of competition among major powers anymore - it's one in which the major powers have (or had, until 1/20/01) mostly harmonious interests. That was Kautsky's heresy, no?
Doug
