【明報專訊】Last week India's Ministry of Defence announced that the Australian navy will participate in the 2020 Malabar maritime military exercise expected to be held next month. As the US and Japan are already regular participants in the military exercises, Australia's rejoining means that the US, Japan, India and Australia are joining forces again in the maritime military exercise after 13 years. It also means that after the four countries held a foreign ministers' meeting under the Quadrilateral Security Dialogue (or the Quad) mechanism in Tokyo early this month, they will meet again for another joint operation in the Indo-Pacific, which is seen as a breakthrough in military co-operation under this mechanism.