Conflict of Interests (1986)

From the introduction:
Conflict of interests is an adventure designed for use with STAR TREK: The Role Playing Game. Up to eight players can roleplay members of diplomatic teams from either the United Federation of Planets or the Klingon Empire...

In this adventure, players will divide themselves into two diplomatic mission teams, each consisting of four representatives. Once on Sheridan's World each team has one week to assess the colony's success and to attempt to influence the local inhabitants in favor of their own governments. The adventure culminates with a plebiscite in which the inhabitants of Sheridan's World decide their fate and the political implications of that decision.

From the cover of the Klingon Intelligence Briefing:
This adventure module also includes a separate book, a Star Fleet Officer's Intelligence Briefing on the Klingon Empire. The briefing includes information on prominent family lines, Klingon society, and new information on the little-known, non-military side of Klingon life. This information further rounds out that included in FASA's The Klingons supplement.