Final answer:
The ongoing Mexican drug war is primarily caused by drug cartels and trafficking. These cartels fight for control of profitable smuggling routes into the United States, using violence and corruption to maintain their dominance.
Step-by-step explanation:
The primary cause for the ongoing Mexican drug war is C. Drug cartels and trafficking. The influence and power of Mexican drug cartels have increased significantly, particularly after the fall of Colombian cartels in the 1990s. These cartels generate enormous profits through the control of drug smuggling routes and territories, leading to conflicts for territorial dominance. They are known to use intimidation, corruption, and violence to maintain their operations, smuggling illegal drugs such as cocaine, marijuana, and heroin into the United States.
Since 2006, when the Mexican government declared war on these cartels, there has been a significant escalation in violence. This includes numerous deaths of both military and police officers, as well as civilians caught in the crossfire. Armed conflicts between rival cartels, the militarization of the drug war, and the high demand for drugs have all contributed to making drug trafficking the central issue fueling the drug war.