SummaryState sovereignty manifests itself through all the powers a state exercises over its territory: it is one of the basic components of sovereignty according to international law. Sovereign power involves controlling territory with a degree of efficiency sufficient to prove the existence of the state. But according to some, state sovereignty has now become less and less a matter of territorial control, and international law is now witnessing an erosion of the significance of territory. While the author admits the plausibility of this opinion when applied to states belonging to closely linked economic unions as the EEC, he challenges this statement when applied to Canada, even given the framework of the U.S.-Canada Free Trade Agreement. In Part I, this article gives a full account of the Canadian positions dealing with legally valid acquisition of territories through effective control and other means. It points out how Canada has been coherently committed to protect its territorial sovereignty in all the border and territorial disputes in which it was and is still involved. It explores how this country deliberately also committed itself to effectively controlling its vast terrestrial, aerial, and maritime territories.From this perspective, the author exposes in Part II the rather protective Canadian legal attitude when dealing with private international interests in Canada: how foreign investors are selectively allowed to own, control, possess, or otherwise acquire an interest in any part of Canadian land or real property through specific substantial rules or conflict of law rules; how Canadian federal and provincial laws deal with expropriating foreign-owned property or with foreign judgments affecting the same. In the view of the author, all these territorialist features strongly convey the idea that Canada still attributes a prime role to securing close control over its territory within its global policy of sovereignty and independence.