This a reproduction on a postcard of the poster in the collection for details, see Notes for ID # 1178. This is apparently one of a series of nine such cards, "How the War Will End: A Summary In 9 Posters." (The poster itself does not indicate that it is part of a set.)
It was not uncommon for persuasive maps to be reproduced and distributed in postcard form, as an inexpensive means to reach a larger audience than posters. The collection includes five examples: ID #1179 (Le Plan Pangermaniste), #1203 (Englands Not), #1238 (Portugal N'est Pas un Petit Pays), #2256 (Portugal Is Not a Small Country), and #1182 (L'Entente Cordiale).