The Espionage Act in the US serves a similar role to the broader treason laws in many other countries, which often include the kind of offenses included within the Espionage Act. So, while "espionage" and "treason" are, indeed, different words, being prosecuted for what German law calls treason may well be more analogous to being prosecuted in the US under the Espionage Act than it is to any other US offense.