Tactful person (8)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tactful person</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for diplomat that I've seen before include "person with negotiating skills" , "Tactful type" , "Official engaged in international negotiations" , "Official representing a country abroad" , "eg Ambassador" .)