RAAF scrambles plane to observe Chinese naval exercise

Australia scrambled an air force surveillance plane earlier this month to monitor an unannounced Chinese military exercise that took the emerging superpower's ships closer to Australian territory than ever before.

In what observers say is a significant strategic development, China carried out combat simulations at the beginning of the month between Christmas Island and Indonesia in an apparent flexing of its growing naval muscle.

China had not announced the exercise. When Australia became aware that the three Chinese vessels were sailing across the waters to the north, the Royal Australian Air Force sent an AP-3C Orion maritime surveillance plane from RAAF Base Edinburgh, near Adelaide, to observe.

The Chinese flotilla - two destroyers and a landing ship able to carry hundreds of marines - came closer than the People's Liberation Army Navy ships had ever come while carrying out such an exercise. It was the first time China had carried out a military simulation in Australia's maritime approaches.

The three warships came through the Sunda Strait between Java and Sumatra, skirted along the southern side of Java - taking them close to Christmas Island - before turning north through the Lombok Strait next to Bali.

Analysts stressed China's move was legal - taking place in international waters - and not inherently hostile. But it did constitute a signal by Beijing that it meant to become a truly global naval power, which fundamentally changed Australia's strategic position. Rory Medcalf, director of the Lowy Institute's international security program, said China was sending a message it considered the Indian Ocean part of its maritime domain as well as the Pacific.

''It should focus Australian minds because for decades Australian defence policy has been based on the view that Indonesia is between us and the great powers of East Asia. That's no longer quite the case,'' he said.

The signal was directed not at Australia but to the Asia-Pacific region more broadly - including a message to the United States and India that they could not blockade the vital sea lanes through the Strait of Malacca in the event of a crisis of conflict with China.

Hugh White, professor of strategic studies at the Australian National University, said the exercise was ''a very vivid demonstration of how far and fast those changes are happening''.

''It doesn't mean that this exercise is threatening to Australia but it does show how much the region is changing and how dangerous it is to assume - as successive Australian governments have done - that China can rise economically … without it making a fundamental strategic difference to the region.''

A spokesman for Defence Minister David Johnston said Australia had not been informed in advance but there had been no obligation for China to do so.