Turkey's former chief of staff recently walked out of a courtroom in protest of what he considers a sham trial against him. He has been imprisoned for months. So are the former heads of Navy, Air Force and Gendarmerie, as well as deputy chief of staff and hundreds of serving and retired military personnel -- all accused of terrorism or involvement in a coup plot. Yet no coup took place in Turkey over the past decade and the military has receded in influence in line with European norms. In the most famous of Turkey's various ongoing coup investigations, the "Sledgehammer" trial investigates whether or not a 2003 war exercise was in fact a coup plan, around 250 members of the Turkish military are in jail. That includes almost 60 serving generals and admirals -- roughly 16 percent of the generals in the Turkish military. None of the suspects have been convicted. As international concerns over the rule of law in Turkey increase, what do trials against military officials mean for NATO? With tensions along the Syrian-Turkish border rising, can NATO count on its second-largest military to play an effective role in global strategic concerns? For Turkey to play a credible role in the next 60 years of NATO, allegations against Turkey's highest military ranks need to be cleared up. This is not to say generals should be above law or that the Turkish military should not be under civilian control. Turkey's traditionally staunchly secular military has overstepped its jurisdiction on several occasions in the past and tried to engineer politics. Since coming to power in 2002, the moderately Islamist Justice and Development Party (AKP) has done marvels to bring the military under civilian control as part of reforms toward EU criteria. But the ongoing investigations have many troubling aspects. What began as an attempt to come clean with the darkest pages of Turkey's history has spun out of control. Instead of bringing the military under civilian control, a chain of accusations and lengthy pre-trial detentions without verdicts in the famous Ergenekon and Sledgehammer cases risk undermining the rule of law and trust in Turkey's state institutions. While Turkey's democratic transformation is important for people in Turkey and also for Europe, a military in paralysis can easily destabilize the country. Additionally, an unprecedented number of journalists are imprisoned, and concerns of the abuse of anti-terrorism laws are growing to alarming levels in Turkey. For Europe, this should be weighed in the context of enhanced cooperation on security as well. Today, many inside and outside Turkey believe that the cases constitute to political processes based on fabricated evidence. It is unclear who benefits but it is clear that the costs and liabilities are rising for Turkey but also for NATO. Take the Sledgehammer case. Turkish and American technical forensic experts established that large amounts of evidence documents were forged. Lawyers who have alleged such forgery of evidence in court found themselves subject of new investigations along with their clients soon after. The credibility of these trials will be of crucial importance for the future of Turkey. The foundations of the state providing NATO's second-largest army have become implicated: the functioning of the rule of law, the separation of powers and the impartiality of the judiciary. I find it hard to believe that NATO's second-largest army and such a significant member of Western security since the Cold War has been run by terrorists all along. But politicians should not take the seat of the judge. It is Turkey's judiciary and government that are responsible for ensuring the rule of law, fundamental freedoms, due process and fair trials. The European Parliament joined the European Commission in proposing to open up negotiation chapters for Turkey on the judiciary and fundamental freedoms. This should boost the stagnated EU accession process and could help Turkey make the necessary transitions and reforms in order to meet international standards of democracy, good governance and the rule of law. But given the grave character of the accusations and the consequences of the verdicts of the trials against military leaders in Turkey, NATO itself should play a role. It should send observers to Turkey and monitor the trials of high-ranking (or retired) military officials. In times of heightened tensions in the Middle East, there is no room for ambivalence about the reliability of NATO's second-largest army.