Military Events allow the player to conduct larger Offensives than the OC value of the card would allow. All military events have a Logistic value.
This is my confusion. Panama Canal was the first time I noticed this, though I see other cards do the same thing. It seems like Military Event is the catch all for an event that isn't a Reaction, Resource, or Political Event. But this stands in sharp contrast to the above citation, this is the source of my confusion. I will amend my rules copy to reflect that the above citation is not true.