It played successfully in Chicago for several months before Woods opened a production on Broadway at the Hudson Theatre on July 22, 1918.
The entry of the United States into World War I against Germany creates conflict between Karl and the others.
When Karl discovers that his money has funded a bomb that sinks the troop transport carrying his son, he changes his position on the war.
The play has a happy ending when Billy returns home, having been saved from the sinking ship.
[1][2] Dorothy Parker gave the play a positive review in Vanity Fair's October 1918 issue, saying: "Friendly Enemies... is simply driving them wild over at the Hudson Theatre.