Terran Intelligence is "...spread horribly thin over far too many stars..." (Captain Flandry, p. 344) and can send only one man to Betelgeuse. The Time Patrol is spread thin over too many years and can send only one man to Tyre.
Intelligence guards an Empire which Merseians threaten in the Betelgeuse region. The Patrol guards a history which Neldorians threaten in Tyre.
Intelligence and the Patrol are like equivalent organizations in Space and Time. Maybe Dominic Flandry and Manse Everard are parallel cross-sections of a single multidimensional reality?
Stars, years, empire and history are powerful and evocative concepts. These are two definitive series by Poul Anderson.