China's military is equipped with advanced weapons that present the biggest threat to mainland Australia since World War II, a think tank says.
Australia's geographic isolation - which has been a major strategic advantage for decades - no longer deters the rising Asian superpower, according to a Lowy Institute report.
"China has the military and industrial potential to field a long-range power projection capacity that would dwarf anything Japan threatened Australia with during the Second World War," the study said.
China's People's Liberation Army (PLA) is today "developing the military capability to put at risk Australia's territorial integrity".
China's missile arsenal and its long-range bomber force are the most concerning elements of the country's recent arms build-up, the report said.
Australia's north-west could be targeted by China's DF-26 intermediate-range ballistic missile (IRBM) from its bases in the South China Sea.
Chinese missiles risk a major military power shift in the region.
"Already by far the world's largest, this force continues to grow at a rate that only makes sense for the purpose of severely threatening US and allied capabilities in the western Pacific," the report said.
In addition to the IRBMs, China's H-6K bomber aircraft flown from naval air bases could target large parts of Australia.
China's air force would be also greatly enhanced by the development of a new bomber - the H-6N aircraft - that could be refuelled in mid-air.
The aircraft is capable of carrying nuclear weapons and has a flight range of about 9000km, reports say.
China's ability to militarily target mainland Australia from long distances means an invasion would not be necessary to grab control, the Lowy Institute said.
"The sheer ability of the PLA to take such extreme steps places pressure on decision-makers whose actions are weighted with the fear that force might be used against them."
Countries with the highest military expenditure in the world