Even by the already horrific standards of the Syrian civil war, the violence in the city of Aleppo during the past week has been brutal. Russian and Syrian government airstrikes killed more than 300 people, targeted the last vital scraps of medical services in rebel-held areas, and used bunker-busting bombs in what UN Secretary-General Ban Ki Moon called "new depths of barbarity." The attacks only added to the 25,000 people who have died in Syria since a temporary truce ended in April, according to the Syrian Observatory for Human Rights. Yet with the carnage in Syria only getting worse, neither Donald Trump nor Hillary Clinton discussed the Syrian civil war during Monday night's presidential debate, to the dismay of analysts and activists.