China's naval drills with Russia are aimed at testing the U.S. and its allies in the Pacific region, analysts say. China and Russia have expanded military cooperation in both scale and sophistication since 2022, the year Russia launched its full-scale invasion of Ukraine. Their military cooperation also offers practical benefits to both sides, analysts say. Koizumi earlier this month stressed that security in Europe and the Indo-Pacific is increasingly connected, citing increased cooperation among China, Russia, and North Korea. "I conveyed the need for NATO-IP4 cooperation has never been greater considering the trilateral cooperation among China, Russia, and North Korea," he said.