The Panama Canal was a strategic-mobility vulnerability

The Panama Canal was an Achilles' heel in US naval mobility because it was a fixed point connecting Atlantic and Pacific forces. Soviet support for Cuba carried an added strategic benefit by placing pressure on both the United States and the canal route. If a canal were struck or blocked, carriers and escorts might have to move rapidly around a continent. Nuclear escorts could not remove the chokepoint, but they could help preserve mobility when the shortest route failed.