In the early hours of June 9, a Chinese Jiangkai I frigate entered waters near Japan's disputed Senkaku Islands, called the Diaoyu by China. The move sparked an immediate response from the Japanese government, which summoned the Chinese ambassador at 2 a.m. to lodge a protest.
When the islands were nationalized by Japan in 2012, incursions by Chinese ships and aircraft increased dramatically, from practically zero to sometimes several per day. This most recent incursion was unique because it was the first time China has used a naval vessel instead of a coast guard or other state ship to venture near the islands.
One senior Japanese defense official said the warship's presence meant "the level of crisis has gone up one notch." However, both the frigate's route and Japan's response may actually have confirmed that Japan really has the upper hand in the Senkaku dispute.