The possible recruits see nothing worth dying for, and see nothing wort protecting, neither.
They see useless foreign combat, for ideas and peoples foreign to them.
With all the years of wars on the nightly news, since the Vvietnam War, some folks don’t want any part of it, or worze, to have granny watch her kid get blown to bits on live TV.
That’s exactly how it was right after the US entered WWI. Very little enthusiasm, that’s when the propaganda and Sedition Acts kicked into gear.