What is the theme in Idiot's Delight by Robert E. Sherwood?

Although the situation of Idiot's Delight revolves around the political situation in Europe, the play is ultimately a love story, with two lovers who spent a night together ten years earlier realizing that they are still in love. The years have changed both Harry and Irene, to such an extent that they do not recognize each other immediately. From their very first meeting, Harry does not know who Irene is, confused by her changed hair color and her strongly Russian pronunciation of her name; still, he is fascinated with her and shows excessive interest in her relationship with Weber. It is not until act 2, scene 3, that they have some time alone together, and Harry explains that she reminds him of the redheaded girl he knew in Omaha.