Do not share the secrets of one liaison partner with another.
This is known in the intelligence business as Third Party Rule.
These days, good intelligence is about international cooperation i.e. liaison relationships between special services.
The Monaco Intelligence Service (MIS) was created on a shoestring of a budget, but with much wit and resourcefulness. As a small service, it needed valuable intelligence from those willing to provide it.
Monaco’s spymaster was able to create liaison relationships with the U.S. Central Intelligence Agency, the UK Secret Intelligence Service, and many other foreign special services strategic to the MIS mission.
The ironclad Third Party Rule is this: You do not, under any circumstances, share what a foreign intelligence service tells you with a third party i.e. another intelligence service (or anyone else).
Liaison relationships were extremely important to MIS.
Monaco’s population comprises of 125 nationalities.
Through foreign intelligence services, MIS was able to run traces on a number of suspect foreign residents and prospective residents and investors.
Foreign intelligence services provided such intelligence to MIS at no cost. It was a brilliant deal for Monaco.
Unfortunately, Monaco’s prince could not grasp this concept; he did not seem to comprehend that everything he always wanted to know about anything was available to him; that, upon request, twenty intelligence services stood ready to send a representative to Monaco at a few days notice to brief the prince on any subject of his choosing.
Unfortunately, the subjects of the prince’s choosing had more to do with unusual sexual escapades than affairs of state.