Phil in SF quoted Judgment at Tokyo by Gary J. Bass
In the weeks after Japan finally surrendered to the Allies to end World War II, …
The Tokyo trial never knew that, as Kasahara has shown, General Matsui Iwane pressed for a swift assault on Nanjing in the hopes of forcing the surrender of China's government — a lacuna that allowed the general to present himself on trial as passive and doddering, rather than an active commander.
— Judgment at Tokyo by Gary J. Bass (Page 819)
new word (have seen before but haven't bothered to look it up until now): lacuna
• an unfilled space; a gap • a missing portion in a book or manuscript