Pardek + Wormhole Negotiations
From Jason Winter : Q@decipher.com

One of the strengths of the Romulans (no, really, they have them!) is a strong mix of both Diplomacy and Treachery. A dilemma like Wormhole Negotiations is a natural, since it requires large amounts of either skill. And Pardek with Diplomacy x2 and Treachery is the ideal man for the job.
Trivia note: "Unification" is not the only Star Trek two-parter Malachi Throne (Pardek) has appeared in. He also played Commodore Mendez, who presided over Spock's court-martial in original Trek's "The Menagerie."