U.S. Naval War College war game found multiple reasons why U.S. should immediately ratify UNCLOS

Players agreed that the United States should ratify UNCLOS as soon as possible. Players cited a number of reasons why UNCLOS ratification should be considered as a national imperative. First, without ratification, the United States does not have a seat at the table despite the fact that UNCLOS was originally drafted with U.S. interests in mind. Second, the United States has not yet ratified this treaty and other states that have ratified it have the ability to modify it while the United States remains dormant. If the United States ratifies UNCLOS after modification by other states, then it must be accepted as modified, with amendments that may not be favorable to the United States. Third, failure to ratify UNCLOS will mean that the United States will not be able to file for an Expanded Continental Shelf Claim in order to extract resources beyond the 200 mile Economic Exclusion Zone (EEZ). Fourth, ratification would increase the certainty or predictability of the future security and political environment that industry desires in order to invest in economic development of the Arctic region. Thus, non-ratification risks the loss of future economic interests by the United States.

Non-ratification of UNCLOS may also negatively impact other U.S. interests and other regions. Taking note of U.S. non-ratification, other states may disregard key aspects of international law, such as Freedom of Navigation (FON) or rights under the EEZ. They may feel that if the U.S. government does not recognize the rules, then why should they? The impacts of nations withdrawing from the convention or challenging it could spill over into unintended consequences elsewhere, such as conflict in the South China Sea.