Two former Australian prime ministers have reflected on Australia's security pact with the United States, naming climate change and China as key current challenges the nations are facing.
John Howard and Julia Gillard spoke on the 70th anniversary of the Australia, New Zealand, United States Security Treaty (ANZUS) at an event hosted by the United States Studies Centre.
The treaty was signed in 1951, and since then the countries have joined together to fight in countless wars, including in Vietnam, Iraq and Afghanistan.
Mr Howard and Ms Gillard reflected on the alliance and looked to the challenges that lie ahead.
Afghanistan: What went right and what went wrong
Then prime minister Howard was in Washington on September 11 when planes hit the twin towers of New York's World Trade Center and he invoked the ANZUS security treaty to join the fight against Al Qaeda.
He insists the 20-year war was not a failure but acknowledged there are questions to be answered about how it ended.
Ms Gillard was the third prime minister to oversee Australia's role in Afghanistan with another three leaders to follow after her.
She said the United States and Australia must reflect on how they managed the war and the withdrawal.
"Clearly there is a need for deep reflection by us, by the United States and by many around the world given the circumstances in Afghanistan," she said.
Ms Gillard said the US and its allies also need to consider how to support the people of Afghanistan from afar.
"There are a range of tools that we have in our hands from aid and development on the one hand, ranging through to sanctions on the other and many nuances in between and we need to work through that," she said.
China: The greatest foreign policy challenge facing Australia
Asked to reflect on the current challenges facing Australia and the United States, Mr Howard said China had become "belligerent" and "aggressive".
Mr Howard described the American alliance as "hugely" important and said Taiwan was the "elephant in the room".
"I would be very surprised if the Chinese launched any kind of full scale attack on Taiwan, because they would fear that there would be massive retaliation from the Americans and they would almost certainly come off second best," he said.
"There will obviously be increasing pressure in different ways put on Taiwan by the Chinese and this is going to be a difficult issue."
Mr Howard praised the development of the Quadrilateral Security Dialogue group but insisted it was critical Australia continued to work with China, describing it as a "delicate" relationship.
"In dealing with China, we should never lose sight of how valuable she is as an economic partner [and an] export destination," he said.
Climate change: A national security issue
National security is at the heart of ANZUS but Ms Gillard said climate change must also be considered as a threat to both nations.
"The challenge of climate change is a challenge in every sense," she said.
"It is also a security challenge, likely to lead to major and unregulated movements of people including in our region of the world so collaboration and cooperation on that looms large."
A group of Torres Strait Islanders recently accused the Australian government of failing to address the climate impacts that threaten their homes and Prime Minister Scott Morrison has faced pressure from world leaders to do more to address climate change.
Mr Morrison has repeatedly refused to commit to a target of net zero emissions by 2050, despite all of Australia's major trading partners committing to the goal.
Instead, the Prime Minister has said Australia will "preferably" reach that target by 2050, arguing that the government's response would be led by technological change.
