In the TNG episode "Face of the Enemy", Deanna Troi is speaking with N'VEK, a Romulan, and they have the following conversation:
N'VEK: M'ret had questioned the repressive activities of the government and was in danger of being imprisoned. He is willing to take this risk in order to protest Romulan policy and support the dissident movement.
TROI: You're part of Ambassador Spock's underground movement.
N'VEK Yes. If we are able to deliver M'ret safely, Spock is hopeful that we can establish an escape route for the thousands of dissidents who live in fear of their lives. Now you realize why we are willing to go to such extraordinary lengths, even kidnapping you, to make sure we succeed.
TROI: You've given me the identity of a Tal Shiar officer. Is there a real Major Rakal?
N'VEK: There was. She was killed so that you could take her place. Only a member of the Tal Shiar would have the authority to alter a ship's mission.
Did Spock know the details of N'Vek's plan and that Major Rakal would have to be killed? Or did he give N'vek his mission and let him worry about the details?
I assumed that N'vek lied about Major Rakal being killed to avoid having to answer more questions, but Deanna being telepathic, would have detected if he was lying.
Spock is aware what he's doing is dangerous and people could die, but I find it disturbing that Spock would knowingly let someone die just so Deanna could take her place.