It means "make (someone who would stop at nothing) balk." It's an obsolete expression, based on a old European stereotype of Turks as lawless bloodthirsty warriors - people who would not balk at anything. (Edited to add: This expression is obsolete and very obscure, because it is derogatory to Turks. The behavior of Turkish warriors during any of the multiple wars between Turkey and various European countries through history may have been seen as ruthless and bloodthirsty; but, in reality, the average Turkish person is no more ruthless or bloodthirsty than the average person anywhere.)