Exiles (TOS novel)

Introduction (blurb)
Tensions remain high as the United Federation of Planets, the Klingon Empire, and the Romulan Star Empire attempt to maintain their fragile post-Dominion War peace in the wake of the brutal attack by the mysterious Watraii that ended with the loss of Admiral Pavel Chekov. When Admiral Uhura receives intelligence regarding a Watraii base that may contain more than one surprise, she sends Ambassador Spock, Captain Saavik, Ruanek, Captain Montgomery Scott, and Lieutenant Commander Data on a covert mission to learn its secrets...

But the true secrets of the Watraii have their basis millennia in the past. In the time of Surak, Vulcans were at a crossroads, on the cusp of either embracing logic or succumbing to emotion and destroying themselves. With Surak's blessing, a group of Vulcans left their turbulent homeworld to find their destiny among the stars -- but the stars prove themselves even more unforgiving than the sands of Vulcan's deserts, as Karatek, the reluctant leader of the exiles, must struggle to hold the community together.