To settle the problem, conferences were held at Geneva in 1958 and 1960 and at Caracas in 1974, but no agreement was reached. At Caracas the United States pushed the twelve-and two-hundred-mile limits, providing freedom of navigation and of scientific research in the economic zone was assured for all nations—"a balance between coastal states' rights and duties within the economic zone"—but some nations appeared hesitant about diluting their sovereignty in the zone.
Finally, in 1982 a comprehensive United Nations Law of the Sea Treaty agreement was reached that established the twelve-mile limit for territorial waters and the two-hundred-mile "exclusive economic zone" that the United States had pushed for. The historic pact deemed the world's oceans the "common heritage of mankind" and represented a dramatic shift away from Grotius's notion that the seas were free owing to their boundlessness. Now the seas were understood to be a zone of interdependence in which all nations (including landlocked ones) had a stake. Although the Law of the Sea Treaty substantially affirmed American notions about the freedom of the seas, the administrations of Ronald Reagan and George H. W. Bush refused to sign it because of restrictions it placed on private enterprise regarding deep seabed mining. In July 1994 the Clinton administration, after negotiations leading to the modification of the deep seabed mining provisions, signed the pact; the Senate, however, perceiving that the treaty still hindered the U.S. freedom of action on the high seas, refused to provide the two-thirds majority needed to ratify it. As of 2001 the United States was not a signatory to the treaty, which went into effect on 16 November 1994 after ratification by sixty nations.