For example the Brits had their Secret Intelligence Service and the Special Operations Executive plus they worked together with the Polish, French and Czech intelligence services. The Germans had their Abwehr and Sicherheitsdienst. The Americans created the Office of Strategic Services etc etcSpying was a hard business. Recruiting trustworthy individuals, training them, providing them with false identities, necessary paperwork and foreign currency was not easy. Inserting them into an enemy country was difficult with the majority being caught in a relatively short time. Even those that survived could usually only gather information of limited value.
The Germans built up large spy networks in neutral countries like Spain, Turkey, Sweden and Switzerland but they did not have similar successes in the US and the UK.Prior to WWII they had compromised the USAAF’s most advanced bombsight but during the war their attempts to insert agents all (?) failed.
In the UK their attempts were so clumsy that the Brits not only captured the spies but in many cases convinced them to change sides and send false information to the Germans.Does that mean that the Germans failed to get any useful information from these countries during the war? Not quite. Although the Germans didn’t have spy networks in the US and UK they were able to acquire some accurate information on Allied war production (and possibly other areas).
How could they have done so? Although they didn’t have spy nets that doesn’t mean that there weren’t other countries that did. Diplomats and businessmen of neutral countries learned a great deal by talking to Allied officials and some of this information was leaked or sold to the Germans. At the same time there was an exchange of information between Germans, Italians, Japanese and Hungarians.For example in Sweden Karl-Heinz Kraemer, secretary of the German legation in Stockholm, was able to gather valuable information on US and UK war production mainly through his contacts in business and government circles. In 1944 the Allies considered Kraemer to be one of the most dangerous German agents and they were worried that he might compromise the security of operation ‘Overlord’.
One of Kraemer’s best sources was the Japanese military attaché in Sweden, general Makoto Onodera. In 1944-45 they regularly met and exchanged information.General Onodera
In Europe one of the top officials of the Japanese intelligence service was the military attaché in Sweden, general Makoto Onodera.