When are terrorists not terrorists? When, as with the PKK, national self-interest gets in the way

While most of the Western world agrees that Islamic State is a terrorist group, there is far less agreement about whether other violent groups are terrorist, particularly when it comes to non-Islamist groups – the Kurdish separatist Partiya Karkeren Kurdistani (or PKK), which translates as Kurdistan Workers' Party, being a case in point.

The United States presently lists 58 groups as "foreign terrorist organisations", Britain 67 (plus 14 in Northern Ireland), Canada 54, New Zealand 20 and Australia 20 (but not the same 20 as New Zealand). To some extent, these large differences reflect different proscription criteria, national self-interest and whether a group is judged to pose a threat to one's nationals. All list the PKK as terrorist, though its continued categorisation as such is questionable on definitional grounds.

The PKK seems to be listed by Canada, Britain and the US mainly because they are members of NATO, and the PKK's target, Turkey, is also in NATO. Australia is not part of NATO – in our and New Zealand's case, listing of the PKK probably has much to do with self-interest in ensuring we have continued access to Gallipoli for Anzac Day commemorations. We reviewed its status again in August 2015 and re-listed it – no doubt in part because we need cooperation from Turkey to identify Australians travelling through Turkey to fight in Syria. Paradoxically, many Australians, male and female, have gone to fight for the PKK since its inception and, as far as I am aware, none has been prosecuted on return to Australia.

As well as its terrorist organisation list, the US categorises Iran, Sudan and Syria as "state sponsors of terrorism", though some of its less-savoury Middle Eastern allies are more culpable when it comes to responsibility for politically motivated killings.

Should the PKK be categorised as a terrorist group (in the sense that it's politically motivated, mainly directs its attacks against non-combatants, intends to shock and terrify, and aims to achieve a strategic outcome)?

When the PKK was established by Abdullah Ocalan in 1978, it adopted a communist or Marxist ideology, but was primarily committed to creating, by force if necessary, an independent Kurdish state, or Kurdistan, in the Kurdish-majority areas of south-east Turkey, north Syria, north Iraq and north-west Iran.

After the Cold War ended in the early 1990s, the PKK remained predominantly secular and increasingly emphasised its role as a Kurdish nationalist movement. It has focused on autonomy for Kurds within Turkey and promoting Kurds' rights – specifically the right to maintain a separate Kurdish ethnic identity. It also aims to monopolise Kurdish political power in Turkey. In terms of ideology, it now has a moderate leftist or socialist orientation.

The PKK announced a unilateral ceasefire in March 2013 and has been involved in peace talks with the Turkish government – but sporadic PKK attacks continued, probably by elements within the PKK opposed to any ceasefire. The PKK often claimed to be responding to Turkish security force attacks and atrocities. The PKK's targets are invariably the Turkish military and police – the main elements of the Turkish state deployed against Kurdish separatist movements.

No doubt there is fault on both sides. Turkey certainly has a poor human rights record, with documented massacres or mass killings of Kurds in 1930, 1978, 1987, 2009 and 2011, and it has repressed and discriminated for decades against its Kurdish population, including by trying to destroy its separate culture.

In July 2015, the PKK announced the ceasefire was over because the Turkey government reneged on its promise to give Turkish Kurds greater autonomy. In August 2015, the PKK announced it would accept a ceasefire with Turkey under US guarantees – but the US clearly didn't want to get involved. Since the latest truce collapsed, Turkish security forces have probably killed hundreds of PKK members, while the PKK has killed dozens of Turkish security force members.

While this has been going on, the PKK has been active in the fight against Islamic State; it is said that PKK forces helped tens of thousands of Yazidis escape Islamic State-encircled Mount Sinjar. The PKK was also involved in the fight to save the Syrian city of Kobani.

Nonetheless, in Istanbul on January 23, US Vice-President Joe Biden condemned the PKK as a "terror group plain and simple" and a threat to Turkey "like the IS group", while hailing the Turkish government's cooperation in the fight against jihadists. Biden pleased his hosts with a ringing denunciation of the PKK's "outrageous" attacks. This was a fairly blatant bid to gain Turkish support for the US military campaign against Islamic State and to deflect Turkey's anger away from the US over its support for PKK-linked Kurdish militant groups that the US has been supporting in the fight against IS.

For the European Union, too, the PKK and Kurdish human rights have become expendable now that the EU needs Turkey's cooperation to stem the flow of migrants to Western Europe.

On balance, the PKK seems hard done by but, due to the concurrence of external needs for Turkey's support mentioned above, it now has few friends and will be out in the cold for the foreseeable future. Its changed fortunes will allow the Turkey government to be more proactive against Kurdish separatists in Turkey and border regions – as long as Turkish military operations don't undermine the US's use of Kurdish forces against Islamic State in northern Iraq and northern Syria.

Given that the PKK has been mainly engaged in armed conflict with security forces, it should really be categorised as an insurgent movement rather than a terrorist one, particularly since neither Britain nor the US lists the far more extreme Afghan Taliban as a terrorist organisation. (Canada and New Zealand list the Taliban as terrorists, but Australia doesn't.)

Australia's proscribed terrorist group list is in the main conservative and reasonably sensible compared with those of the US and Britain, though some of our inclusions and exclusions are puzzling given the inclusion criteria: that a group is "directly or indirectly engaged in, preparing, planning, or assisting in or fostering the doing of a terrorist act; or advocates the doing of a terrorist act".

One notable omission from the Australian list is Jamaah Ansharut Tauhid (or JAT), the Indonesian extremist group formed by Abu Bakar Bashir in 2008 as a splinter from Jemaah Islamiyah, which was responsible for the Bali bombings. In 2012, the US State Department and the United Nations placed sanctions on JAT and designated it a terrorist group. In August 2014, Bashir pledged JAT's allegiance to the leader of Islamic State, Abu Bakr al-Baghdadi. This now seems the most likely group to mount terrorist attacks against Australians in Indonesia.

Considering the emphasis these days on international counterterrorism cooperation, including last week's counterterrorism talkfest in Kuala Lumpur, you would expect there to be agreement between allies on such a basic issue as which terrorist groups should be commonly listed to facilitate coordinated action against them. Surprisingly, this is not even true for Australia and its closest allies. There is an old cliche about one man's terrorist being another man's freedom fighter, but we could go further and say that even among the Five Eyes nations (Australia, Canada, New Zealand, Britain and the US), one nation's terrorist groups reflects one nation's interests.

Clive Williams is an adjunct professor at the Australian Defence Force Academy and an honorary professor at the Australian National University's Centre for Military and Security Law.