In the wake of Turkey's failed coup in July, the government launched a military incursion into neighboring Syria to clear "Islamic State" (IS) terrorist militia fighters from its border. Turkey has also stepped up its campaign against Kurdish militants in the country's southeast as well as northern Iraq. Experts told DW both IS and the Kurdistan Worker's Party, or PKK, pose a threat to Turkey.

"The resolution about Syria goes [over] well, but there is a hidden side to it. There is a huge fight between the US and Russia west of the Euphrates and this fight has reached a climax as high as in the Cold War days," said Ibrahim Cevik, a security and terror expert at the Turkish Centre for International Relations & Strategic Analysis (TURKSAM). "The lack of control in Syria, the fact that guns lack control and terrorists are walking freely, will hurt us more."

Syria, Iraq policy

Turkey and Russia brokered a ceasefire deal between Syrian government and opposition forces that took effect on December 30. The country has been embroiled in civil war since 2011, and the conflict has had a direct impact on the security of neighboring Turkey.

The Iraqi army, meanwhile, is attempting to recapture IS-controlled Mosul. Ankara considers the situation in the city a significant threat to its national security, and has sought to take on a larger role in the operation.

Nihat Ali Ozcan, a security and PKK expert at the TOBB University of Economics and Technology, said that 2017 will not be a good year for Turkey "because the ecosystem in the region - in Iraq and Syria [specifically] - is changing very quickly and there are reasons related to that."

"Secondly, there are many terror organizations active in Turkey and they target each other, the state and the public," he said. "Both PKK and [IS] and on the other side the [banned far-left] Revolutionary People's Liberation Party-Front (DHKP-C) - they are all active.”

The United States, the European Union and Turkey list the DHKP-C group as a terrorist organization.

The first police officers went on trial in Istanbul last week in connection with the failed coup

Crackdown sparks backlash

Ozcan said the government purge following the July 15 coup attempt could also pose a security threat.

"There are some problems with the state institutions responsible for preventing this. Many people have been suspended, reassigned, reappointed or arrested in the gendarmerie, the army, the police, the judiciary and the penal institutions due to [alleged ties with] the Gulen movement," he said.

President Recep Tayyip Erdogan has accused US-based cleric Fethullah Gulen of being behind the failed coup.

Ozcan said that the government has politicized important government positions all the way up to the presidency. "When you put all of this together, I think this year security will be a significant problem for us," he said.

The Council of Europe, the continent's 's leading human rights organization with 47 member states including Turkey, said last month that over 125,000 people in the country had been dismissed from their jobs as of December 9, and almost 40,000 people had been arrested amid the government purge.

'Signal' for 2017

Mesut Hakki Casin, a professor of International Relations at Ozyegin University Faculty of Law and an international terrorism and security strategy expert, said that the precision of the New Year's Eve attack on a nightclub in Istanbul, which left 39 people dead, suggested to him that it was planned, and the fact that it was done after midnight sends a clear message for 2017.

"I think it gives a signal that in 2017 terror will disturb Turkey," he said. "I think it was an organized attack… For the first time an entertainment venue has been targeted in Turkey.”

IS on Monday claimed responsibility for the attack, which was carried out by a lone gunman still at large. The militant group said it was revenge for Turkish military involvement in Syria and described the targeted nightclub as a gathering point for Christians celebrating their "apostate holiday."

Turkey has been shaken by numerous terrorist attacks in the past year-and-a-half and IS has been blamed for at least half a dozen of them.

IS has taken credit for numerous attacks abroad as it fights to hold onto territory in Syria and Iraq

Kurdish tension

Last month, two bombs exploded outside a soccer stadium in Istanbul, killing 44 people. A car bomb killed at least 13 soldiers a week later in the central city of Kayseri. Kurdish militants claimed responsibility for both of the attacks.

Since a two-and-a-half-year ceasefire ended in July 2015, Turkey has continued to clash with militants from the PKK, which is labeled a terrorist organization by the US, EU and Turkey, in the southeast.

Tensions flared recently after lawmakers from the country's main pro-Kurdish Peoples' Democratic Party (HDP) were arrested and local HDP mayors in the southeast were detained and replaced by government officials.

Ozcan said that he expected the PKK to escalate its attacks in the spring.

"In terms of the PKK issue, it looks like tensions will increase as well as the clashes," he said. "Towards the spring, the trend could increase. It was calm due to weather conditions."