The Abbott government confirmed on Wednesday that it plans to extend airstrikes into Syria against Islamic State targets. The national security committee met on Tuesday to approve a plan to conduct the aerial operations.

The attorney general, George Brandis, has made assurances the airstrikes would be legal because Isis “conducts aggressive attacks on Iraq from bases within Syria … and we are at war with Isil on behalf of the people and constitutional government of Iraq”. (Isil is Brandis’s preferred term for Islamic State.)

But can the Australian government just start bombing Syria, and are there domestic or international legal concerns? Here are five key facts about our plan to bomb Syria.

1. Who makes the decision on whether to bomb Syria?

Bombing a foreign country is a cabinet decision that can be made by the government of the day. This means it needs to go to cabinet for approval and forms part of powers of the executive.

Constitutional law professor Geoff Holland from the University of Technology Sydney said: “The declaration of war or engagement of military is part of the executive prerogative.” This means that once cabinet signs off, our armed forces can start planning the strike.

2. Can the Abbott government bomb a foreign country without parliament approving the decision?

The government could conduct bombings on Syria without any form of parliamentary approval necessary. At a later date it might need to engage with parliament over budgetary appropriations, though, in the event more funds were needed.

3. If Australia decides to conduct airstrikes on Syria, are there any concerns this might breach international law?

Members of the United Nations are required to refrain from the threat or use of force against other countries, and conducting an airstrike in Syria would likely be considered such a use of force. But there are ways that Australia could justify or defend this in international law.

4. What kind of justifications could Australia rely on in international law?

There appear to be key two arguments the Australian government could rely on to defend the bombings. The first justification is the notion of the collective self-defence of Iraq. This relates to a longstanding international legal principle that would permit Australia to intervene, and is what Brandis strongly alluded to in his comments about the strikes.

It’s problematic, though, because a number of significant international law cases have outlined that it can only be relied on for the defence of one state against another state – and Isis is not considered to be a state, at least not one recognised in law.

Professor of international law at Sydney University, Ben Saul, said: “It’s clear that Iraq is under armed attack by Isis, so it has a right of self-defence against them in its own territory, it’s entitled to make requests of foreign powers to assist it, but why it’s problematic is that the conventional view is that you can only use self-defence when it is by a state force.”

There has been some dispute over this application though, and Saul said the position in international law was now in flux. After the September 11 attacks, the UN security council endorsed the US action in Afghanistan in response to the terrorist attacks. It expressly recognised the US’s right to individual self-defence in response to acts of terrorism.

The second justification Australia may rely on is that they are exercising self-defence individually against Isis. This is one of the arguments that may have been relied on by the United Kingdom government over the drone strike on two British nationals announced earlier this week. Saul said while this could also potentially be relied upon, it could only be invoked in very particular circumstances where there was a specific threat against Australia.

Neither justification seems entirely clear. Writing in the Conversation, Kevin Boreham, a lecturer in international law at Australian National University, described Australia’s potential air missions as “a legal grey area.”

5. What are the possible ramifications for Australia if international law is breached, and is there any domestic recourse?

The ramifications for Australia violating international law are pretty minimal. A case could be brought against Australia in the International Court of Justice by Syria or another state. But in the unlikely event that were to happen, there are no consequences in domestic law that would bind Australia by any such decision.

As always, though, the political ramifications may be more significant if the airstrikes escalate into Australia playing an even greater role in armed conflict in Syria.