Take steps toward real port security.(OTHER VOICES)

If there is a silver lining to the DP World debacle, it is this: Congress is focused on improving "port security." But we must be careful what we wish for. Congress killed a deal that had nothing to do with port security on the grounds that it would undermine our port security.

Two key principles should guide the government's efforts to enhance port security. First, the greatest threats to our ports are posed by arriving vessels, cargo and crew. Our ports may be attacked using vessels or cargo as weapons. Or they may serve as gateways to smuggle people or weapons inland. But ports are unlikely to be the target of a terrorist already in the U.S.

This means that we should …