 Why doesn't Malloy go to the peace talks himself?
Every man in the Diplomatic Corps who developed a twitch or a quirk was shipped to Saarkkad IV to work under Bertrand Malloy, Permanent Terran Ambassador to His Utter Munificence, the Occeq of Saarkkad. And, Malloy knew, his own position was not unimportant in that war. To have shown himself to one of them would have meant instant loss of prestige. It was Bertrand Malloy's job to keep the production output high and to keep the materiel flowing towards Earth and her allies and outposts. She came in through the door, a rather handsome woman in her middle thirties, clutching a sheaf of papers in her right hand as though someone might at any instant snatch it from her before she could turn it over to Malloy.
 Malloy has a psychological disorder that prevents him from leaving the house. He also hates aliens.
 Malloy is too sick to travel to the peace conference. He also hates aliens.  Malloy needs to stay on Saarkkad IV to keep the drug supply lines flowing.  Malloy is too far from Saarkkad V to get to the peace conference on time. He also hates aliens.  Malloy has a psychological disorder that prevents him from leaving the house. He also hates aliens.