You might find a few example of military officers counseling against war in history, mainly in liberal democracies, but you'll probably find a lot more the other way round. Even then the council is usually more about when, where and how rather than whether to do it at all.

Not all militaries are meaningfully accountable to political leadership, and not all political leadership cares about morality anyway (cough Russia cough). In free democracies yes, the military is at least to some extent held accountable to the government and the people, but we still end up with atrocities only a few of which are ever held to account, such as the Balkans war. Or in places like Chechnya or eastern Ukraine (so far) nobody is ever held to account. A few is a heck of a lot better than none, because it can act as a deterrent and an encouragement to the organisation to do better next time though, of course.

Realistically, the decisions about what weapons the military should have, how they should be designed and what safeguards should be in place are all political decisions. Only how they are employed in war is really in the hands of the military, and in liberal democracies even that is sometimes a political decision (e.g. using a submarine to sink the Belgrano in the Falklands War.)