Rashi on Babylonian Talmud Sanhedrin 2a (comment on "false prophet")
רש"י סנהדרין דף ב.א - ד''ה נביא השקר
במלחמת הרשות ־ כל מלחמה קרי רשות לבד ממלחמת יהושע, שהיתה לכבוש את ארץ ישראל.
"Permitted/optional war": Every war is considered permitted/optional except Joshua's war which was to capture the Land of Israel. [Translation by Righteous Indignation]

Suggested Discussion Questions:

1. Joshua captured the Land of Israel because God commanded him to. How does this affect our understanding of Rashi's comment?

2. With this knowledge, what is a permitted/optional war? Is there a such thing as an obligatory war?

3. If every other war is considered optional, what does that say about Jewish views on the necessity of war? What are your own opinions on the use of force to resolve conflict?

Time Period: Medieval (Geonim through the 16th Century)