Tom,

As you stated it is all a matter of definition. :)

Sure is!

A nation can be imperialist without being an empire. A representative modern definition of "imperialism" is:

'The practice of one country extending its control over the territory, political system, or economic life of another country. Political opposition to this foreign domination is called "anti-imperialism" '

IMHO there have been examples of both for well over a century.

He may be out of fashion, but in 1916 Lenin described Imperialism as the final stage of Capitalism, characterized by export of capital rather than goods, establishment of a "rentier" strata of society that is involved in no industry but derives super profits by "clipping coupons", increasing monopoly power and super-profits systematically extracted from less developed countries.

Are we there yet? ;-) http://www.marxists.org/archive/lenin/works/1916/imp-hsc/