Failure of U.S. to ratify UNCLOS could cause entire international agreement over EEZ to collapse
Senate delay may prove costly since treaties without leadership can decay. Shortly after World War II, a unilateral move by the U.S. in the Truman Proclamations of September 1945, declaring ownership of the continental shelf seabed resources and announcing a policy for extended US jurisdiction of coastal fisheries far out to sea beyond the then dominant three mile limit, diplomatically backfired for the U.S. as the Proclamations resulted in a bevy of national claims by other nations. These nations claimed jurisdiction or even sovereignty over waters as much as 200 miles off their coasts - a development fraught with negative consequences for U.S. naval operations, shipping, and distant water fishery interests. The next three decades of U.S. oceans diplomacy were dedicated to containing this explosion of offshore claims. The solution was formulated with the leadership and consistent support of the U.S. and was formalized in the comprehensive package of new law in the 1982 Law of the Sea Convention. The Convention's central innovation was the creation of a third type of ocean zone from the new 12-mile outer limit of the territorial sea to 200 miles past which the traditional "freedom of the high seas" is retained. That in-between zone of ocean (the Exclusive Economic Zone) mixes coastal ownership and high seas freedoms in a way that allows the U.S. to have sovereign rights in the fish for 200 miles off its coasts but still allows the U.S. Navy to operate up to 12 miles off of other coastlines. The crucial point is that the Exclusive Economic Zone is a complex zone and is, by its nature, unstable, easily tending to gravitate to more and more ownership claims by the nearby coastal state.
The Law of the Sea Convention sets forth the deal, has the institutions to enforce the deal, and may be one of the main things that prevent a collapse of zones from recurring.