Confronted by the militancy of longshore unions, port operators have deployed automation, in part to limit their vulnerability to labor troubles. Not coincidentally, dockworkers tend to look suspiciously at robots and other forms of innovation, divining threats to their livelihoods.

Even a short strike at East and Gulf Coast ports could disrupt U.S. supply chains until 2025, according to one expert.

For the first time since 1977, East Coast port workers are on the verge of a strike. Here's what's at stake, for both workers and consumers.