If all cultures have the right to self-determination, what of the right of self-determination of a culture that determines it wishes to conquer other cultures? In order to respect its right of self-determination, one would have no choice but to permit its aggression.
No, because that is not self-determination, that is aggression. It is, in other words, the deliberate valuation of one's own culture's power over another culture's and a denial of that other culture its
right to self-determination.
The right to self-determination, more specifically, refers to the right of any culture to make decisions for itself that do not interfere with the rights of other cultures to make decisions for themselves.
To make a symbolic analogy: I have the right to swing my arm wherever I want so long as it does not hit your nose.
In other words, it is self-determination unless you personally disagree with it, in which case it is not.
Your analogy is good, but it is also false. Laws against violence are are limitations on self-determination, all laws are.
The right to self-determination is not an absolute in any legal or ethical theory, it can always be abridged for the greater good. This we call this abridgment of rights for the greater good rule of law. The only question is whose law, whose rule.
Modern democratic governments believe that they derive the right to impose the rule of law from the consent of the governed. That is a lie. They derive the right to make law from the consent of a majority of the governed, the rest are held hostage by force of arms. Disagreeing with the law does not exempt one from it.
It is permissible to impose rule of law by force of arms. It is often necessary. It is usually necessary. The only question is whose law and whose arms.
Rights are not physical things, they are not tangible things, they are not real things. They are ideas, invented by men and imposed by law. Laws are not physical things, they are not tangible things, they are not real things. They are ideas, invented by men and imposed by violence.
When systems are law clash, they tend to be normalized to each other, making them more compatible. This can be done through violence, or through negotiations, which carry the implicit threat of violence.
When two totally incompatible systems of law clash, conflict is an inevitable necessity. The inability to normalize relative to each other means that one or the other or both must eventually be destroyed.
Compromise requires understanding that values and laws different than your own are perfectly valid. It also requires a willingness to empathize with someone who is different from you.
The Borg are a rarity in that their very simple law is totally incompatible with our own more complex system of laws. Normalization is impossible, destruction is the only option. Even so, it is unwise to call them evil.
Evil is a label that makes it easier to kill. For this reason, it is a very useful label to impose on one's enemies. Nazis are evil, so we can kill them without feeling bad; Jews are evil, so we can kill them without feeling bad. It serves no other useful purpose. And it is dishonest. It distorts our perceptions of ourselves as much as it distorts our perceptions of our enemies. It makes peace more difficult, it makes mercy more difficult, it makes forgiveness more difficult, and it makes their opposites far too easy. We can label our enemies as evil because of their actions and then we can feel confident in our righteousness as we do exactly the same things, worse even.
No man calls himself evil. We all know in our hearts that out actions, no matter how abhorrent that they may seem, are absolutely right. Once you label yourself good, and your enemy evil, there is no line that cannot be crossed. The greatest atrocities are not committed by a demon or a devil, but by a saint.
Anyone deluded by absolute conviction is in danger of violating their own values. And this is why I oppose labeling the Borg as evil. This is why I oppose labeling anyone as evil.
Certainly, I oppose those who are injurious to myself, and those that I value, but I must be honest with myself about that opposition and I demand no less from anyone else, lest opposition turn to righteousness and righteousness turn to enormity.