Not to ensure the flow of commercial goods, which may not move, but to ensure the transport of military equipment in a time of war.
Should the Union try to interfere with this, they will be jailed at the barrel of a gun.
If the work is so damned important, pay the longshoremen what they want, and be done with it.
If the work isn't important enough to keep management from locking out the workers, then why have the gov't step in and start pointing guns?
You statist FReepers amaze me.