Um...No. No person has the right to order another person to be violated. Any person who would even consider doing such should not be in command in the first place.
But that's patently untrue. The very idea of a military organization hinges on the concept that person A can order person B to lose his or her limbs, eyes, half the face, and/or life, and person B has two options: to refuse (in which case he or she will be very harshly punished, typically with death, unless he or she can prove the order was illegal), or to obey.
There are other dimensions to this as well. Person A can also order person B to get captured by the enemy and be subjected to whatever cruelties the enemy is famed for. There's always the slim theoretical chance that person B can fufill his or her orders without getting maimed, killed or captured, but there is no obligation for person A to ensure the existence of such a chance, nor fault in him or her for ordering person B to his or her fate.
Against this background, it really sickens me to hear people say that a woman should not be "violated" on the course of her duty. Who the fuck cares if said woman is in psychological distress for a while, or gets her vagina torn, or whatnot? People are dying and being dismembered out there!
The chastity of a woman is not sacrosanct in a military organization. Sure, it's one of the nice principles the organization theoretically exists to protect - but its own members are exempt from the protection by definition. Similarly, the military is supposed to protect people from dying, but it achieves this by sending its own people to die.
It's a different matter how threats and protections work within a military organization. Troi should be safe from rape or coercion attempts from her colleagues. But there's no requirement for the colleagues to protect her from rape or coercion by outside forces if such protection would hinder the completion of a mission and endanger other people.
The specific case being discussed here is a non-starter: Troi was asked to give very little to protect a lot - a few nightmares vs. the lives of an entire starship crew and possibly of every person on Earth as well. Had Picard not exploited Troi in this occasion, he (and she) should have been subjected to the harshest of Starfleet punishments for treason.
Timo Saloniemi