Major Barbara stages a question the Salvation Army has always had to answer for itself: what happens when the money that feeds the poor comes from the people profiting off their poverty? Barbara Undershaft is a Salvation Army officer working the London slums when her estranged father, an arms manufacturer, and a whisky distiller both offer the Army large donations. Her superiors accept. Barbara, sickened, resigns on the spot.
George Bernard Shaw did not leave his own opinion offstage. His preface to the published play, titled in part "The Salvation Army," steps forward in his own voice and quotes an actual Army officer defending exactly the practice that breaks Barbara: the Army, the officer said, "would take money from the devil himself and be only too glad to get it out of his hands and into God's." Shaw goes on to argue that nearly all money in a modern economy is tainted by exploitation somewhere along its path, so refusing a donation on moral grounds accomplishes nothing except leaving the poor hungry a little longer.
That leaves the play and its own preface pulling in different directions, and neither this article nor the database resolves it for the reader. Shaw the essayist defends the Army's fundraising as clear eyed realism. Shaw the playwright spent an entire drama taking that same realism seriously enough to let it break a good woman's faith in her own organization. Major Barbara is not an attack on the Salvation Army. It is a considered argument that its hardest compromise deserves to be looked at directly rather than waved away, from a writer who, by his own account, ultimately sided with the compromise.