International trade boosts our economy, but U.S. seaports need major improvements to maximize the benefits of trade. Bloomberg reported a couple months ago that congestion at West Coast ports is so severe that shippers are diverting a growing share of traffic to Canada. The Wall Street Journal reports today that the problems are continuing.

One issue is the aggressive labor union that controls the West Coast ports:

For more than a month, a rotating cast of about a dozen container vessels, bulk ships and tankers has sat anchored just outside the ports of Los Angeles and Long Beach, some waiting as long as eight days to berth.

… Uncertainty over contract negotiations between terminal operators and the West Coast Longshoremen’s union has further aggravated the congestion, local officials and economists say.

Businesses up and down the West Coast that rely on the ports for importing and exporting goods have expressed concern over the protracted negotiations between the International Longshore and Warehouse Union, representing workers at West Coast ports, and the Pacific Maritime Association, which represents carriers and terminal operators. ILWU members have been working without a contract since a six-year pact expired July 1.

In recent weeks, the PMA has accused the union of slowdowns at the ports of Seattle and Tacoma, Wash., and withholding some critical workers in Los Angeles and Long Beach, contributing to the current congestion. Some longshoremen walked off the job Oakland, Calif., last week, aggravating concerns over a widespread labor disruption during the holiday shipping season.

Port employers as well as retailers and manufacturers say their greatest fear is the possibility of a total shutdown across West Coast ports—similar to a 10-day worker lockout in 2002 after labor talks failed. The shutdown cost the U.S. economy several billions of dollars, industry groups say. Mr. Louttit of the Marine Exchange said the disruption at one point left 65 ships sitting at anchor off the Southern California coast.

The solution to these labor problems is straightforward: Congress should repeal “collective bargaining,” which is a euphemism for monopoly unionism. In other words, it should repeal the National Labor Relations Act (NLRA), which confers unjustified powers on unions and encourages them to disrupt workplaces.

The share of the private-sector workforce that is unionized has plunged for decades because unions make no sense in the modern fast-paced economy. But the unions that hang on in some industries cause a lot of trouble, as we’ve long seen with the high-paid longshoremen on the West Coast. I don’t imagine that NLRA repeal is on President Obama’s agenda, but it is a reform that policymakers should pursue down the road.