It's imperialist by definition: imposing one's one laws inside the territory of another sovereign state. That is what empires do.
Well, actually, that's not the definition by any major accepted dictionary I know of.
Also, if extraditing a person can be considered "imperialist", than literally everything country in the world is imperialist, since every country extradites. In fact, embassies of all nature would be imperialism, as would ambassadors. I don't think enforcing your rule in a foreign land automatically makes you imperialist, you have to be in control of the country, and be a part of an empire.
Imperialism
noun
1. the policy of extending the rule or authority of an
empire or nation overforeign countries, or of acquiring and holding colonies anddependencies.
2. advocacy of
imperial or sovereign interests over the interests of thedependent states.
3. imperial government; rule by an emperor or empress.
4. an imperial system of government.
5. British. the policy of so uniting the separate parts of an empire withseparate governments as to secure for certain purposes a single state.
Empire
1.a group of nations or peoples ruled over by an emperor, empress, orother powerful sovereign or government: usually a territory of greaterextent than a kingdom, as the former British Empire, French Empire,Russian Empire, Byzantine Empire, or Roman Empire.
2. a government under an emperor or empress.
3. (often initial capital letter) the historical period during which a nation isunder such a government:
a history of the second French empire.
4. supreme power in governing;
imperial power; sovereignty: Austria's failure of empire in central Europe.
5. supreme control; absolute sway:
passion's empire over the mind.
6. a powerful and important enterprise or holding of large scope that iscontrolled by a single person, family, or group of associates:
The family's shipping empire was founded 50 years ago.
7. (initial capital letter) a variety of apple somewhat resembling theMcIntosh.
Empires are governments, lead by an emperor, with absolute control, over a large expanse of territory. The U.S. doesn't have absolute control over Afghanistan so, it's not really imperialism, as in, we don't control them. Nor are we ruled by a Dictator.
Now, that may be your own personal definition of an "empire", but it's too vague to really be of any practical use or reference actual Empires, like the Roman or Chinese empires.