(FORTUNE Magazine) – The International Longshoremen's brief strike against a dozen East Coast ports from Maine to Virginia may cause some shippers to steer clear of those harbors for a long time. Philadelphia, Norfolk, Baltimore, and New York, for instance, might lose valuable cargo and jobs to safer harbors, such as Savannah, Charleston, New Orleans, and even Los Angeles, where strikes are not in prospect. Longshoremen on Northeast waterfronts face increasing competition from non- union facilities as well as railroads. A Japanese automaker may find it cheaper to land cars on the West Coast and send them by rail to New York than to ship them directly to the East Coast. Still, the strike has shown that the longshoremen, whose ranks have dwindled with the spread of containerized shipping, remain a formidable force.