Why cant Tin Pei Leng be appointed the Minister for Defence instead in singapore?

Based on the reactions she provoked from the public by her candidacy as part of the GRC, I don't think even LHL will risk the same reactions from the foreign community to appoint her as the Minister for Defence. Can you imagine her letting go, "I don't want to say" at the Shangri-La Dialogue 2011 while stomping the ground? But then, she can be quite entertaining.