22 CFR 120.51: Reexport.

(a) Reexport, except as set forth in § 120.54 or § 126.16 or § 126.17 of this subchapter, means:

(1) An actual shipment or transmission of a defense article from one foreign country to another foreign country, including the sending or taking of a defense article to or from such countries in any manner;

(2) Releasing or otherwise transferring technical data to a foreign person who is a citizen or permanent resident of a country other than the foreign country where the release or transfer takes place (a deemed reexport); or

(3) Transferring registration, control, or ownership of any aircraft, vessel, or satellite subject to this subchapter between foreign persons.

(b) Any release outside the United States of technical data to a foreign person is deemed to be a reexport to all countries in which the foreign person has held or holds citizenship or holds permanent residency.