Sector principle

The sector principle, also known as the sector theory, is a principle in international law which asserts that territorial claims in the polar regions shall be determined by longitude lines. The territories are thus divided into wedge-shaped sectors, each one having their apex at the geographical pole with their base extending down to an arbitrary latitude. The sector principle has historically constituted the basis on which territorial claims in the Arctic have been made, although its usage has failed to gain universal international recognition.

The principle is today more or less abandoned; Canada stopped referring to it in 2006 and the 2010 boundary negotiation in the Barents Sea between Norway and Russia contains no mention of the sector principle. It has arguably seen a broader implementation in Antarctica, whose territorial claims are divided into sectors. This division is, however, not seen as an extension of any particular state's territory due to the large bodies of water separating the continent from other land masses.

Arctic

The principle was first proposed in 1907 by Canadian senator Pascal Poirier. He was delivering a speech in support of his own motion which sought to claim possession of the Arctic Archipelago on Canada's behalf. Poirier's motion was originally dismissed, and his Sector theory deemed a "one-man idea". The principle would however gain immense traction in subsequent years.