China and Russia could exploit U.S. non-party status to renegotiate UNCLOS in ways adverse to its interests

The example of China and Russia's flouting of the convention's norms also presents the possibility that the treaty could be renegotiated to become more favorable to those countries' interests. UNCLOS as currently written is extremely favorable to U.S. interests, codifying the rights of freedom of navigation and passage that are important to maintaining its global power status, according to Titley.

“The real strategic threat for us not being a [party to UNCLOS] is if anybody at some point wants to change the rules of the game … we're not going to have a seat at that table,” Titley said. UNCLOS “basically codifies up a world in which the U.S. is kind of the number one dog. And so now by not ratifying this, as the world changes, and maybe if that situation changes, we're not even going to be in the room when—if this ever gets looked at again. … It's frankly pretty hard to see that another [international legal] regime would be as friendly to U.S. interests as is UNCLOS. That's a real danger.”

Another key risk connected with the United States not being a party to the treaty is that the treaty itself is weakened by lack of U.S. participation, because it is important as a big coastal state and a major economy, according to Jensen.