 Williams akabatsira nyika dzinenge makumi maviri nemamwe masangano epasi penyika mumisangano mikuru yerunyararo yenyika, kugadzira mutemo uye kuronga mutemo, uye kuvaka bumbiro remitemo mushure mekurwisana kuburikidza nebasa rake semutungamiri uye mubatsiri wePublic International Law Policy Group. Williams anoonekwa semushandi wezvemagariro evanhu nokuda kwenzira yake inoshanda uye itsva yekupa rubatsiro rwe pro bono kune vatengi. Akashanda senhume mu Dayton Agreement nhaurirano Bosnia-Herzegovina, Rambouillet Agreementuye Paris nhaurirano Kosovo, Ohrid Agreement nhaurirano Macedonia, uye PodgoricaBelgrade nhaurirano dzeSerbia neMontenegro. Akapawo mazano kumapato muKey West nhaurirano dzeNagorno-Karabakh, Oslo neGeneva nhaurirano dzeSri Lankan Civil War, nhaurirano dzeGeorgian-Abkhazian conflict, uye hurukuro dzerunyararo dzeSomalia. 