Accountability is generally accepted to be conditional on awareness and consent, and infants are capable of neither. I also like pointing to the Israelites forty years in the wilderness: The biblical basis is that, because the Israelites refused to enter Canaan when spies reported the natives apparent military supremacy, God decreed that none of them would EVER be allowed to enter, but would instead wander the wilderness until everyone above age twenty had died. What's interesting about that is that it means the Bible states God held the entire Israelite nation responsible for doubting Him and forbade them to ever enter Canaan BUT explicitly excused everyone under the age of consent. In essence, minors got a free pass. It could be argued that was because they had no say in whether to invade (notwithstanding the fact many of them would have been expected to participate), but I trust you see why I consider the incident a kind of precedent, or at least illustration of a principle.