Experts react to Australia's decision to build nuclear-powered submarines for the first time, a major strategic shift as the country weighs strengthening defences against a rising China. International Security Program Director at the Lowy Institute Sam Roggeveen told AFP that the announcement came as a bit of a shock to most observers and marked a "significant escalation" in military involvement in the region. "There was a there was a period of time when Australian leaders would say that our security was to be found in Asia and not from Asia. But this agreement doesn't look like that it looks like a throwback to something earlier," he said. Ashley Townshend, Director of Foreign Policy and Defence at the University of Sydney's United States Study Centre said it was a "welcome development" in improving bilateral access to military technology. SOUNDBITES