There has been a lot of conflict between Russia and Turkey. I think the tension between them intensified when Turkey shot down Russian jets. Now President of Russia Vladmir Putin has been requesting that the former Orthodox Church in Constantinople (Now Istanbul) to be returned back to Orthodoxy because Turkey took that land from the Greeks and changed the Orthodox Church known as Hagia Sophia into a Mosque which is now a museum!
While I agree that the situation between Russia and Turkey are deteriorating quickly since the downing of the Russian jets (note the video Russia claimed showed turkey smuggling in ISIS oil that was later agreed to be not relevant by the international community). However Turkey is both a member of the Balkan Pact and the Agreement on Strategic Partnership and Mutual Support, which allies Turkey with Azerbaijan, Romania, and Greece. Turkey is also a member of NATO--which has been increasing its in presence the Balkans to hold back any Russian expansion. In regard to Putin's comments about the Hagia Sophia, he has made empty threats and vague commands to countries it views as "client states" before; like his threats to Ukraine after the 2008 NATO summit. Thus, due to the above reasons, I believe war between Turkey and Russia is a near impossibility.
That is what people thought with America and Japan, no one thought a war would happen and then Japan bombed Pearl Harbor and so war began. But with Greece, Greece would most likely protest against Turkey because Greece's relationship with Russia is growing every single day especially when yesterday Vladmir Putin visited Greece and met with Prime Minister of Greece Alexis Tsipras and so I can see Greece protesting against Turkey if things were to occur. Also now that Greece and Russia are having a growing alliance it is putting tension on the EU and NATO because Greece and Turkey are both part of those and so tension is building. Also on the day Putin visited Greece Turkish air forces started flying over the Aegean, Turkey has been known to violate a lot of air spaces without permission and they do not like it when people violate theirs and so that is another tension which is building. A war is possible.
While you may be right about Greece's support of Russia I disagree that NATO and the EU would not prevent Russia from invading. While Russia has been making a show of force around the Balkans the EU and NATO still have greater military strength, I think Russia's show of power was probably just power projection to hide their weakness from both Russia's enemies and her populous. The Russian economy is also not in a state where it can effectively stage an invasion, as of 2014 (I couldn't find anymore recent studies) Russia's GDP per capita was at ~8000 according to tradingeconomics.com. On top of all this the U.S. will probably Become involved if it sees an expansionist Russia. As far as Pearl Harbor is concerned the Japanese were already at war with the east Asian powers thus they had both the mindset, support, and materiel to launch an attack
You may be right about Russia's show of power but you have to admit that Russia does have a great strength and could you imagine if some of other big world powers as big as Russia like China and a few others, this could lead to some war between Russia and Russian allies against NATO and there could be a break within NATO because of the countries in NATO that support Russia and there could also be tension between the EU!
Regardless of tension within the EU the majority of the European Union would fight against an expansionist Russia regardless of their relations with Turkey. This would force the members with pro Russia leanings to declare that they would stand with Russia against the EU which I doubt many would do even if they support Russia. In regards to Russia's military might: yes they have a significant armed force, but Russia does not have the economy to support the long term war that would ensue with an invasion of Turkey.
Well then there is China because they have one of the biggest armed, navy and air forces. If they do manage to ally with Russia in this along with other countries then it is possible for Turkey to struggle in this. But yes there will be tension with the EU and NATO! Also it would cause a lot of tension in the UN!
Okay, first of all the U.S. defense budget is equal to the next top 10 defense budgets combined. If the U.S. becomes involved then Russia has nearly no chance of effectively taking control Turkey. Plus China is unlikely to side with Russia as they still hold a grudge from Soviet invasion of Xinjiang. While tension might hurt the EU, NATO, and the UN it would not be long lasting and wouldn't cause any kind of EU civil war.