War II, the Mexican Army had become a strictly professional force focused on national defense rather than political involvement. Mexican Drug War Although violence between drug cartels has been occurring long before the war began, the government held a generally passive stance regarding cartel violence during the 1990s and the early years of the 21st century. That changed on 11 December 2006, when newly elected President Felipe Calderón sent 6,500 federal troops to the state of Michoacán to end drug violence there. This action is regarded as the first major retaliation made against the cartel violence, and is generally viewed as the starting point of the war between the government and the drug cartels. As time progressed, Calderón continued to escalate his anti-drug campaign, in which there are now about 45,000 troops involved along with state and federal police forces. In recent times, the Mexican military has largely participated in efforts against drug trafficking. The Operaciones contra el narcotrafico (Operations against drug trafficking), for example, describes its purpose in regards to "the performance of the Mexican Army and Air Force in the permanent campaign against the drug trafficking is sustained properly in the duties that the Executive of the Nation grants to the armed forces", for according to Article 89, Section VI of the Constitution of the Mexican United States, it is the duty of the President of the Republic of the United Mexican States, as Supreme Commander of the Armed Forces, to ensure that the Mexican Armed Forces perform its mandate of national security within and outside the state borders. Structure The Army is under the authority of the National Defense Secretariat or SEDENA and is headed by the Secretary of National Defence - simultaneously a member of the central government and (the sole) four-star general. His counterpart is the Secretary of the Navy, who is a member of the central government and the sole four-star admiral. The National Defence Secretariat has three components: a national headquarters, territorial commands, and independent units. The Secretary of National Defence delegates overall command of the Army thru the office of Commander of the Army, a divisional general-ranked officer, who leads the service via a centralized command system and many general officers and is appointed and relieved by the Secretary. The Army uses a modified continental staff system in its headquarters. The Mexican Air Force is a separate service under the SEDENA. Recruitment