In these things you have to worry about the other side “capturing” your people, that you sent to represent your interests. Their judgment can be compromised surprisingly easily. Very often happened during the Cold War, especially for instance to OSS people in Vietnam, etc.
This isn’t a simple business.
Its one permutation of the https://en.wikipedia.org/wiki/Principal%E2%80%93agent_problem
Operation Sunrise
Operation Sunrise (sometimes called the Berne incident) was a series of World War II secret negotiations from February to May 1945 between representatives of Nazi Germany and the United States to arrange a local surrender of German forces in northern Italy.[1] Most of the meetings took place in the vicinity of Bern, Switzerland, and the lead negotiators were Waffen-SS General Karl Wolff and American OSS agent Allen Dulles. The meetings provoked Soviet suspicion that the Americans were seeking to sign a separate peace with the Germans and led to heated correspondence between Joseph Stalin and Franklin D. Roosevelt, an early episode of the emerging Cold War.
https://en.wikipedia.org/wiki/Operation_Sunrise_(World_War_II)