The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?

(N/A) According to $Fajan's$ rule,as the oxidation state of the metal ion increases,its size decreases and its charge density increases. This leads to an increase in the polarizing power of the metal ion. Consequently,the metal ion polarizes the electron cloud of the halide ion more effectively,resulting in an increase in the covalent character of the bond.