On 26 November 1941, "Jintsū" became the flagship of Rear Admiral Raizō Tanaka and DesRon 2 under the Philippine Seizure Force, Southern Force, of the Japanese Third Fleet. At the time of the attack on Pearl Harbor, "Jintsū" was based out of Palau and engaged in the invasion of the Mindanao, escorting transports with the IJA 16th Infantry Division and Kure No. 1 Special Naval Landing Force (SNLF) from forward bases in Palau to Davao, Legaspi and Jolo. After the Philippines was in Japanese hands by the end of December, "Jintsū" was reassigned to Rear Admiral Kyūji Kubo's Eastern Netherlands East Indies Seizure Force with DesDiv 15 and DesDiv 16.