U.S. failure to join UNCLOS puts freedom of navigation rights at risk in two ways

First, there is a risk that important provisions could be weakened by amendment, beginning in November 2004, when the treaty is open for amendment for the first time. Currently, for example, the Convention prohibits coastal states from denying transit rights to a vessel based upon its means of propulsion. Some states, however, may propose to amend this provision to allow exclusion of nuclear-powered vessels. Under the Convention, no amendment may be adopted unless the parties agree by consensus (or, if every effort to reach consensus failed, more than two-thirds of the parties present agree both on certain procedural matters and on the proposed amendment). As a party, the United States would have a much greater ability to defeat amendments that are not in the U.S. interest, by blocking consensus or voting against such amendments.

Second, by staying outside the Convention, the United States increases the risk of backsliding by nations that have put aside excessive maritime claims from years past. Pressures from coastal states to expand their maritime jurisdiction will not disappear in the years ahead—indeed such pressures will likely grow. Incremental unraveling of many gains under the Convention is more likely if the world’s leading maritime power remains a non-party.