R. Kook on When Jews Can Separate Into a New Group (29 Shevat)

שו"ת משפט כהן קכה 29 Shevat 5678 (1918)

R. Kook discusses with another Torah scholar in London, R. Tzvi Ferber, when it's ok to establish a new Jewish community within a city. When does or doesn't the prohibition of לא תתגודדו, not making the Jewish people into multiple groups, apply?