[elhombrelibre]

Taken from the article at the link:

http://abcnews.go.com/International/wireStory/heavy-clashes-syria-turkish-border-23023925

"Turkey changed its rules of engagement in 2012 after Syria shot down a Turkish military plane, declaring that any Syrian military element approaching the Turkish border would be treated as a legitimate target."

[SunkenCiv]

That’s the payback part.