Will Eisner created the Espionage feature, and Will Erwin was a pen name used by Will Eisner (Erwin was Eisner's middle name) until he left the feature after 1940. It also became a house by-line as well for future writers.
Writer revision from Jerry Iger to ? by Craig Delich 2013-12-26. The Who's Who indicates that S. M. Regi was a pen-name sometimes used by Jerry Iger, but also by others as a house by-line. It further indicates that Jerry Iger did not write this feature, but that Alex Blum, under this pen-name or by-line, did draw the strip.