"Turkey should remain a NATO member, and we should also work to ensure this. Turkey’s membership is of strategic importance for NATO," said German Chancellor Angela Merkel this week while speaking at the Bundestag against German opposition lawmakers calling to expel Turkey from NATO.

Taking into consideration that NATO is set to hold its annual gathering in London, Merkel's remarks are especially meaningful.

First of all, frankly speaking, Turkey should always be a NATO member, as its role is crucial for the alliance. Turkey's membership was established in 1952 and since then, the global organization has played a central role in Turkey's security and contributed greatly to its integration into Europe and the Atlantic alliance at the same time.

Therefore, it wouldn't be fair to defend Turkey’s expulsion on the grounds of select policies since it has always defended the common values of the alliance. It can be safely said that a NATO without Turkey is a NATO that is less secure, and a Turkey outside of NATO is a Turkey less powerful. In other words, it is true that this is a win-win situation for both sides. In addition, there is actually no mechanism to push a NATO member out of the alliance without its consent, at least not in political terms.

The recent problems have stemmed from Turkey’s purchase of Russian-made S-400 defense missiles; however, Ankara adopted this approach and decision as a result of its multipolar foreign policy. Plus, Turkey always stresses that it wanted to purchase an American air defense system at the beginning, but Washington did not offer a good deal or sometimes even refrained from negotiating sincerely with Ankara.

We should keep in mind that alliances between countries can be sustained despite the occasional policy rift. The parties’ advantages also play important roles. In that sense, the tensions between Turkey and other NATO members can serve to advance inter-alliance bargaining. So, a divergence of policy preferences is not necessarily a reason to end membership.

Turkey having good relations with Russia as a NATO ally is sure to hinder Moscow's domination in the Middle East.

It is also important to reiterate that the geostrategic reasons for Turkey’s membership have not changed. On the contrary, with the empowerment of Russia over the last few years, the world is slowly starting to resemble the Cold War era again; so it is important to balance Russia but on the other hand, the world has changed since the Cold War, so we need bridges between Russia and the Western alliance. Turkey could be the perfect bridge for sustaining good relations with both sides.

In addition, if Turkey left or refused to cooperate with the alliance, it could undermine NATO since we're talking about the second-largest military in the alliance after the U.S.

Likewise, Turkey also has the largest navy in the Black Sea, which is also an advantage for NATO in the region. Would a NATO without Turkey be more secure in the Middle East? Or what about in the Black Sea? Even in Europe? Of course not. In a nutshell, policymakers should set aside their sentimental opinions about current politics when they talk about NATO and Turkey.