In November 1943, the Allies were victorious at the Battle of Tarawa and Battle of Makin in the Gilbert Islands, and in early February 1944 seized critically strategic positions in the Marshall Islands with the Battle of Kwajalein and the capture of Roi-Namur. Realizing that the major Japanese naval base in the South Pacific at Truk was endangered, Kobayashi ordered the naval assets there transferred to Palau. However, before the transfer could be complete, the United States launched Operation Hailstone, sinking a large number of Japanese warships and transports. The Imperial Japanese Navy General Staff blamed Kobayashi for the defeat and relieved him of his command two days later. On 30 May 1944, Kobayashi was forced from active service and on 31 May 1944, he went into the reserves.