When Pentagon chiefs agree with leading business groups, the US establishment has reached consensus. For the third time in 20 years, the US Senate this week set the ball rolling to ratify the UN Convention on the Law of the Sea. Only a handful of countries, including Iran, North Korea and Venezuela, have refused to sign. Both the US Chamber of Commerce and the military chiefs want it. Yet it is unclear whether the White House will secure the two-thirds majority it needs.

The arguments against US ratification are weak. Jim DeMint and Jim Inhofe, the Republican senators from South Carolina and Kentucky, say ratification would violate US sovereignty and constrain America’s navy. Neither view has much basis in reality. Indeed, Leon Panetta, the US defence secretary, says the law’s maritime exclusion rights would facilitate the biggest increase of US sovereignty since it acquired Alaska.

In addition to the benefits that legal certainty would give US mineral and telecommunications companies, it would also strengthen naval security, according to the US Navy. That is why George W. Bush tried and failed to ratify the treaty in 2007. The same went for Bill Clinton and George Bush senior before that.