More to the point, "technology is neither good, nor bad, nor neutral, it just exists". Ultimately all tools can be used for good or bad purposes and what matters is the people who wield them.
This is separate from the argument over whether MAD is philosophically good. MAD is not an argument about technology. "Peace through strength" does indeed require the occasional display of strength, to maintain deterrence. Good and bad (morals) are not the right frame to understand deterrence, rather emotions: fear, confidence, and security.
Solzhenitsyn can be read as either a humanist or an ethicist: either the bridgehead of good is sufficient to redeem everyone from war and morality demands pacifism, or all military doctrines must be submitted to independent review to check that we do not give the "unuprooted small corner of evil" oxygen. Crucially, these are both judgements about ourselves and not about the foes who seek to destroy us, who indeed consider themselves to have "the best of all hearts". In this sense, Solzhenitsyn contributes to the cycle of violence: if both sides are ethicists, and their ethical councils have different conclusions, the result is not just fundamentalism but a fundamentalism justified by ethical review.
Fear, anger, disgust are the ultimate drivers of conflict. Can we conquer them? Of course not, they are the base emotions, part of being human. But can there be a better way of handling them in geopolitics? Yes - if leaders are focused on helping not just themselves feel safe, but their enemies as well. This is the higher level beyond MAD - not mutual fear, but mutual security. This is why USAID was great foreign policy and cheap for its benefits. This is why weapons are sold to allies despite the fact that their interests may not be fully aligned with ours. Weapons are fundamental to security, which at the end of the day is a feeling and not a guarantee against attack or repercussions from an attack, and these feelings of security are what reduces the incidence and frequence of war.