On October 23rd, militants attacked a Turkish aerospace facility near the capital of Ankara. The Turkish government blamed the Kurdistan Workers’ Party (PKK)–a Kurdish insurgent group–and launched retaliatory airstrikes. It is very plausible that the PKK is behind this, given the group’s history. But the group has also tellingly not claimed responsibility for the attack, and the Turkish government has an incentive to blame the group.

Thankfully, terrorism studies scholars have looked into whether and when groups claim attack, and that may give us some insight into what happened here.

The Ankara attack in context

A team of militants attacked the site, with reports of gunfire and explosions. Five were killed, and over 20 wounded. The facility is a key part of Turkey’s defense-industrial base, which produces advanced drones and US-designed F-16 fighters. The Turkish government blamed the PKK and even identified one of the gunmen by name. But the PKK has not claimed the attack.

The PKK is a likely culprit behind the attack. The group has been fighting an insurgency since the 1980s against the Turkish government in defense of the country’s Kurdish minority. Most of its attacks have been in the Kurdish regions of the country, but there have been attacks outside of Kurdish population centers. The PKK’s activities also have an international dimension, as they have ties to Kurds in Iraq and Syria, leading to Turkish attacks on Kurdish targets in those countries. Additionally, Turkey initially objected to Sweden’s membership in NATO, accusing Sweden of being soft on PKK supporters among Kurdish migrants in that country.

Thankfully terrorism studies has explored the conditions under which terrorist groups claim attacks.

But the PKK is not the only terrorist threat Turkey faces. The Islamic State has launched attacks against both government and civilian targets in Turkey, such as a 2016 attack in Istanbul that killed 12 tourists. And earlier this year, ISIS-K–an IS affiliate based in Afghanistan–attacked a Christian church in Istanbul. Al-Qaeda also launched a series of suicide bombings in Istanbul in 2003. There has also been violence by right-wing groups in Turkey.

Thus, there are other groups that may have been behind the attacks. Additionally, the Turkish government may have an incentive to blame this attack on the PKK. Kurdish political parties have emerged as a major electoral threat to the ruling Justice and Development Party (AKP). Discrediting Kurdish political activism by tying it to this attack could thus help the ruling party.

When do terrorists claim attacks?

Understanding who was behind this attack thus depends on figuring out why the PKK would not claim the attack if they had carried it out. Thankfully terrorism studies has explored this topic.

Hoffman points to the competitive environment in which terrorism groups operate as a key factor. Groups launch attacks to gain influence, and this is harder to do with numerous competitors for public support. As a result, they are more likely to explicitly claim an attack if there are other groups operating in an area. Kearns also found competitive environments mattered.

The attack may not be seen as a political win for the PKK.

Abrams and Conrad, by contrast, argue that terrorist groups claim credit when the anticipated political impact of the attack is positive. Kearns found something similar, that higher civilian body count led to a more likely chance of claims, unless the attack killed many civilians.

Kearns, Conlon and Young also argued that groups may actively lie about attack responsibility.

What does this research say about the Ankara attacks?

So what does this suggest about whether the PKK is really behind this?

The PKK could face competitive pressure among other terrorist groups, with IS’ continued threat to the country. But IS is not attempting to represent Turkey’s Kurds, so it is not clear IS’ presence would influence PKK tactics. The PKK may thus see no need to claim the attack.

The attack may also not be seen as a political win for the PKK. There were minimal fatalities, with little disruption of the plant’s operations. It thus may not have achieved its intended goal, and the PKK would want to avoid being seen as failing.

Additionally, it does not fit the sort of attack IS launches. The fatalities were civilians, but connected to a government facility. This is much different from the mass casualty attacks against open civilian targets IS usually launches. Additionally, one of the dead militants is, according to Turkish government reports, a woman, which is common in the PKK but not IS.

There is one potential alternative culprit to the PKK, however. One report noted there have been rumors of a ceasefire developing between the PKK and the Turkish government. It is possible this attack was launched by a faction of the PKK or a more radical Kurdish group attempting to undermine any such deal.