Excurse:
a sally or digression [Merriam-Webster]
Noted on Lawfare, in a book review:
Priemel’s research is prodigious, involving not on the many thousands of pages of the official records of the IMT and NMT, but research in more than three dozen archives in Europe and the United States, as well as the voluminous memoir literature and contemporaneous press accounts of the trials. Across ten substantial chapters, Priemel paints the background to the trials and analyzes the conduct of the IMT and all of the successor trials. For good measure, he offers short excurses on French and British military trials related to the successor trials as well.