KAGOSHIMA, Japan: Helicopters buzzed in the shadow of a smouldering volcano and boats rescued dummies from the sea this week in a show of maritime unity by Japan, the United States and the Philippines.

Japan’s coast guard has held a joint exercise with counterparts from the United States and the Philippines, as the three Pacific nations beef up defense cooperation in the face of China’s expanding maritime activities.

Japan's coast guard will simulate a collision between vessels Friday during joint exercises with the United States and the Philippines seen as a show of unity against Chinese activity in disputed