Book 13 in the Star Trek: Enterprise series.
"The rise of the Coalition of Planets strikes dread within the Romulan Star Empire. They feel its growing reach will cut them off from what is rightfully theirs. The Romulans know that the alliance is fragile, that the correct strategy could turn allies into foes. Perfecting a way of remotely controlling Coalition ships and using them as weapons against one another, the Romulans hope to drive a wedge of suspicion and mistrust between these new allies.
One Starfleet captain uncovers this insidious plot: Jonathan Archer of the Enterprise. Determined not to lose what they have gained, outmanned and outgunned, the captains of Starfleet stand tall, vowing to defend every inch of Coalition space until the tide begins to turn."