"Decided in NSC meeting -- will not sign 'Law of the Sea.' ... " So Ronald Reagan noted in his diary entry for June 29, 1982. That should have been the last word on the topic, 30 years ago.

Three decades later, the United States still has not bought into the United Nations Convention on the Law of the Sea, often called by the clunky acronym UNCLOS. And still, America enjoys the freedom to cross the oceans. A third of our trade travels over the seas. Have we missed out on anything by spurning UNCLOS? No. Reagan got it right.

But, like Barnabas Collins, UNCLOS is back from the grave.

The Obama administration has been talking up the convention for the last few weeks, revving the engines in preparation for a run at getting the Senate to approve ratification. The next step: hearings in the Senate Committee on Foreign Relations, chaired by Sen. John Kerry, D-Mass.

Though a huge fan of UNCLOS, Kerry had been holding off on hearings. Most observers chalked this up as an attempt to give the committee's ranking Republican, Dick Lugar, some political breathing room. An UNCLOS booster, Sen. Lugar, of Indiana, faced a strong primary challenge from a conservative candidate. By keeping UNCLOS on the back burner, Kerry was giving Lugar one less questionable stand to defend. But last week, shortly after Lugar lost the primary, Kerry scheduled the first UNCLOS hearing, for this Wednesday.

The first panel will feature Secretary of State Hillary Clinton, Defense Secretary Leon Panetta and Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff. Before the hearings are concluded, all the Joint Chiefs of this administration will doubtless sing the treaty's praises in public. But senators may well wonder: If UNCLOS is so invaluable to our national security, why haven't these guys been out stumping for the treaty over the last 30 years?

If these were real hearings, rather than staged UNCLOS commercials, there would be little reason to call the chairman of the Joint Chiefs as a witness.

America needs nothing from this treaty to provide for its national security. UNCLOS advocates say signing on will give America a seat at the table for mediating maritime disputes. Try selling that rationale today to the Philippines and other Asian countries that signed on to UNCLOS with similar assurances. They now find themselves being browbeaten by Beijing and its claims in the South China Sea. Rather than providing restraint, the convention has given China one more weapon of lawfare to bully its neighbors into making concessions.

In the decades ahead, the biggest factor determining the freedom of the world's most important sea lanes will be the capacity of the U.S. military. After all, the original rationale for drafting the convention was to codify "traditional" laws of the sea. Those traditions came about only because there were strong navies to enforce them.

At the end of the day, UNCLOS is a piece of paper that can't defend us. But it does open us up to legal disputes and economic exploitation. Far better that Congress embrace its constitutional duty -- to provide for the common defense -- by ensuring that America has a military capable of protecting us.

Under Reagan, America's ambition was to build and maintain a 600-ship navy. Under President Obama's defense agenda, the U.S. won't be able to field half that number. Yes, today's naval ships are better than those built 30 years ago -- but the world is still the same size, and even modern ships can only be in one place at a time.

Rather than lobby for a treaty we don't need, the White House should be fighting for the Navy we do need.