MEXICO CITY—The notoriously violent Jalisco cartel has responded to Mexico’s “hugs, not bullets” policy with a policy of its own: The cartel kidnapped several members of an elite police force in the state of Guanajuato, tortured them to obtain names and addresses of fellow officers and is now hunting down and killing police at their homes, on their days off, in front of their families. It is a type of direct attack on officers seldom seen outside of the most gang-plagued nations of Central America and poses the most direct challenge yet to President Andrés Manuel López Obrador’s policy of avoiding violence and rejecting any war on the cartels. But the cartel has already declared war on the government, aiming to eradicate an elite state force known as the Tactical Group which the gang accuses of treating its members unfairly. “If you want war, you’ll get a war. We have …