Article 35 of the United Nations Convention on the Law of the Sea states that "Nothing in this Part affects: ... the legal regime in straits in which passage is regulated in whole or in part by long-standing international conventions in force specifically relating to such straits". Article V of the Boundary treaty of 1881 between Chile and Argentina established a legal regime for the Strait of Magellan, and in a diplomatic letter to major shipping nations in 1873, Chile promised freedom of navigation through and neutrality within the strait.[64][65]