By Professor Don Rothwell
As military intervention in Iraq and Syria becomes increasingly possible, it's worth looking at the legality of sending jets or troops back into the Middle East, writes Professor Donald Rothwell.
As the Abbott Government continues to talk up possible Australian military intervention in Iraq and Syria to combat Islamic State fighters, with Defence Minister David Johnston describing the Australian Defence Force being at a "high state of readiness", there has so far been little discussion as to the legal basis for any proposed military operations.
With the focus in particular upon military operations in Iraq, inevitably comparisons are being made to 2003 when Australia elected to join with the US and a handful of other partners to militarily intervene in that country in an operation designed to rid Iraq of weapons of mass destruction.
Considerable debate and controversy swirled around the 2003 Iraqi mission, principally due to uncertainty as to whether the Saddam Hussein regime possessed chemical and nuclear weapons, and the legal grounds for military action.
Ultimately, the failure to locate weapons of mass destruction in Iraq combined with significant concerns over the legality of that military operation was the dubious legacy of Operation Iraqi Freedom, and those concerns will be raised if full-scale military operations are again being proposed for Iraq.
Defence Minister Johnston has begun to explain the precise role that could be played by Australia in a US-led mission in Iraq, suggesting that Australia's fleet of 24 RAAF Super Hornets could be deployed in conjunction with US and other coalition forces to conduct an air campaign against IS.
No formal request appears to have been made by the US for such assistance, though coalition building is clearly taking place with it being suggested that there is broad support from across Europe and even parts of the Middle East for military action.
International law prohibits the use of force against the territorial integrity of states, and this principle is embedded in the United Nations Charter. The United Nations Charter and international law in general does recognise that military force can be used in limited circumstances.
The first is when the right of self-defence is being exercised. This is a fundamental right of all states as reflected in Article 51 of the UN Charter.
For self-defence to be exercised there first must have been an armed attack, against which a state can respond. In 2001 the international community and the United Nations recognised that the US had suffered an armed attack following the September 11 Al Qaeda terrorist attacks on New York and Washington.
This was ultimately the legal basis for US military intervention in Afghanistan, in which it was joined by coalition partners such as Australia. Self-defence can be exercised when an actual armed attack has taken place, but also in anticipation of an armed attack.
While this extension of the doctrine is controversial, there are no clear examples of Australia seeking to join in military action in reliance upon a right of anticipatory self-defence. Military intervention can also be justified in reliance upon a United Nations Security Council resolution.
This is expressly provided for in the United Nations Charter where Chapter VII of the charter contemplates action being taken by the council in order to ensure the maintenance of "international peace and security".
One of the clearest examples of the UN endorsing such military action came in 1999 when military intervention was authorised in East Timor following the breakdown of law and order in what was then Indonesian East Timor following the UN authorised ballot on the status of that territory.
Australia responded by leading the INTERFET international military force that restored order in East Timor following the withdrawal of Indonesian military forces. Importantly, Indonesia was also agreeable to this military action. To date there is no clear UN Security Council Resolution authorising military action in either Iraq or Syria.
Military intervention is also possible if it is proceeded by an invitation. Minister Johnston has alluded to this being a potential basis for Australian intervention in Iraq; however, he has conceded that given the chaotic state of the government in Baghdad such a request may not be forthcoming until September 10.
Australia has relied upon invitations in the past to intervene in the Solomon Islands in 2003 as part of the RAMSI operation, and also East Timor in 2006 following a request for military assistance.
In the latter case especially, Australia went to great lengths to ensure that all proper procedures were met within the then East Timorese government so that the legality of Australia's military intervention could not be questioned.
As the momentum rapidly builds for a multinational air campaign against IS in Iraq and possibly Syria, the time is fast approaching when the legal basis for any such military action is laid out.
A clear distinction exists between humanitarian aid and assistance, and military operations that are directly designed to neutralise IS. As a current member of the United Nations Security Council, Australia has a particular obligation to uphold the values of the UN Charter and ensure that its conduct is consistent with international law.
The responsibility rests with the Abbott Government to clearly articulate the legal case for any fresh military intervention in Iraq and Syria.
This article originally published on The Drum.