Public debate about reform of our citizenship laws continues to be hampered by a significant categorisation error.

Whether Australian citizenship should be held by traitors remains the heart of the matter. The core issue is how we deal with treachery rather than how we define citizenship.

The revocation of Australian citizenship due to treachery even if considered only as a matter of punishment—and not also as active deterrence—can surely only be discussed properly by addressing the nature, gravity and consequences of the crime involved.

However, because treason and treachery aren’t commonplace crimes, much of the current debate only discusses modes of determining punishment.

Discussion has been further confused by contextual misunderstandings, and by ignorance and misunderstanding of the relevant constitutional and legal history—especially during times when Australia was at war.

Protagonists on all sides of rule-of-law questions end up failing to acknowledge what are essentially wartime circumstances applying to treachery in the current case of Islamic State.

They overlook the relevant High Court rulings, from both World Wars and the Korean War, that firmly established the principle that the defence and security heads of power in the Constitution wax and wane according to the seriousness of the threat.

For example, in regulations under the National Security Act, 1939, ministers were lawfully authorised, subject to judicial appeal, to:

• ban extremist political parties sympathetic to enemy countries and their allies;

• intern enemy citizens, other foreign aliens and naturalised Australians with perceived enemy sympathies; and

• intern Australian citizens by birth who were considered likely to pose a security threat.

That principle is also why, on the other hand, the High Court struck down the Act dissolving the Communist Party of Australia in 1951. Even though Australia was directly fighting communist aggression in the Korean War the High Court judged the nature of the overall threat to national security at that stage didn’t justify the ban.

While the dual international and domestic threats posed by Islamist terrorism aren’t existential in nature, they surely justify more than traditional ‘peacetime’ counter-treachery and counter-terrorism measures.

Moreover, such measures aren’t  ‘ultra vires’ or otherwise contrary to the rule-of-law as some would believe.

Public debate is largely ignoring the obvious relevance of finally closing the 1945–2001 Burchett loophole in our previous treason and treachery laws by the Security Legislation Amendment (Terrorism) Act, 2002.

After the David Hicks case, the 2002 reforms ended the archaic requirement—prohibited by the UN Charter half a century previously—that wars had to be ‘declared’ before alleged traitors could be prosecuted. Armed conflict (war) now exists as a material fact according to international law.

The reforms rightly made it a crime to serve with any armed group fighting against the Australian Defence Force, not just with an enemy nation-state.

While fighting for the Islamic State is therefore illegal, the continuing flaw in the Citizenship Act (Section 35), now recognised by the Abbott government, is that citizenship is only revoked automatically when the traitor is fighting for a nation-state and only if they are a dual citizen or dual national.

Section 35 has never been used nor have similar provisions in previous legislation (back to the first Citizenship Act in 1948) ever been used because of the Burchett loophole, not because automatic revocation somehow contradicted the rule-of-law.

We owe an obligation to our fellow Australians whom we deploy to war and peacekeeping on our behalf to prohibit all acts that intentionally or recklessly assist an enemy fighting them. In particular we must actively deter as well as punish treachery because it unequivocally embodies a rejection of the mutual responsibilities and shared values of Australian citizenship and Australia’s wider obligations as a responsible international citizen.

The current debate also reveals ethical contradictions and a certain loss of perspective.

Few Australians, for example, seem to bat an eyelid at the battlefield killing, by our defence force or our Coalition partners, of an Australian traitor who has chosen to side and fight with Islamic State. Yet there’s quibbling about whether such traitors should, or even can, have their Australian citizenship revoked for such treachery, even when the traitor renounces it.

Such confusion also causes significant moral and practical problems, particularly where it means Australian law enforcement agencies and our defence force are hindered in exchanging relevant intelligence with allied forces fighting in UN-endorsed coalition operations combating terrorism.

Our obligations under international law must be accorded due weight, not somehow be considered universally subordinate to any legal rights traitors might seek to retain in such grave circumstances.

Freely switching your allegiance to a terrorist group such as Islamic State and going to join it in the Middle East is not a normal crime. Australia has national and international responsibilities to deter and counter such serious crime globally, not just punish those traitors we’re eventually able to capture and put on trial in Australia.

Ideally every traitor would be punished by being convicted in an Australian court, but making this a universal precondition for revoking their Australian citizenship causes insuperable moral and practical difficulties. There are several considerations here.

First, you must be able to capture traitors and then bring them back to Australia for trial. If not, treachery remains undeterred. At trial the facts establishing their treachery must be admissible as evidence, despite the obvious difficulties in undertaking an Australia-standard investigation in war zones and countries where the rule of law has ceased to exist.

Second, requiring conviction by an Australian court in all circumstances is unfair, at best, to the men and women we lawfully deploy to confront such traitors on the battlefield, especially before any capture of the traitor for trial in Australia is even remotely, if at all, possible.

Third, the impractical precedent by the Victorian Court of Criminal Appeal in the Jack Thomas case must be overcome. This effectively excludes evidence gathered by the AFP in the relatively lawless countries where terrorists tend to get captured, even when our police advise suspects of their rights and they freely admit the facts.

We must be able to deter as well as punish treachery by revocation of citizenship so battlefield killing is not left as the only alternative where capture and trial is impractical or impossible.