Isn't Iran doing the same by sending Iranian advisors or whatever to Syria, but then to protect Assad? What's the difference? Both Iran and Turkey are trying to influence the situation in Syria, as far as the media is right
The difference is that Iran is doing it with a legitimate government (legitimate in terms of legality) whereas Turkey is giving weapons to insurgents to fight against a sovereign state and government, in order to overthrow it.
Dangerous business, especially since Syria is next door to Turkey.
I think its clear by now that Erdogan has overreached, but more importantly gravely miscalculated and done tremendous harm to Turkeys interests.
Forget the fact that Turkey is no longer seen as "zero problems with neighbours"-mediator. Turkey is now exposed to multiple more security threats, that did not exist before the conflict started.
A de facto Kurdish state formation is taking place along northern Syria, bodering Turkey, via heavily armed Kurdish militias (YPG).
This can be a POTENTIAL (but not guaranteed) severe threat to the republic of Turkey, because of the potential of cooperation between YPG and PKK.
And good luck with the Syrian government assisting you with that, after what you did.
Al Qaeda has a very heavy presence, and they were responsible for the bombing which killed some 40 Turkish civilians. They have threatened with more attacks against the Turkish state.
To put it simply, Turkey royally f.ucked up. Now you must manage the damage that you have done to yourselves.