...of course, there's more to the story - like sending an unescourted liner into waters where Germany had promised to do just this very thing. I'm not a big proponent of active conspiracies, but Wilson (and the Brits) had to know the outcome beforehand....
Among other things the Germans trying to get Mexico to go to war with us didn't help (Zimmerman telegram). Actual, factual evidence of another nation meaning to do us harm.
My GreatGrandfather volunteered as a medical officer; first he was detailed to a camp somewhere in the US South where he wrote notes in triplicate (!) instructing soldiers not to defecate while standing on the latrine seat, among other fine things, then he was shipped to Europe where he contracted the flu on the boat over, almost died in a hospital, then returned home. His maxim thereafter was "never trust the government"