The deployment of such a large federal force specifically for combating the cartels is unprecedented in Mexico -- though at best it will serve only to temporarily disrupt criminal activity in Michoacan, or divert it to other parts of Mexico.

Several cartels, chiefly the powerful Gulf and Sinaloa cartels, are vying for control of Michoacan, which now leads the country in the number of beheadings. The state is valuable to the cartels because its coastline offers many coves and inlets that can be used to receive shipments of drugs from South America for transshipment to U.S. markets. However, while the federal forces are disrupting cartel operations in Michoacan, the drug lords currently there could shift their activities to other coastal states, such as Guerrero or Jalisco. In that case, other ports of entry not solidly under the control of a single cartel, such as the popular tourist resorts of Acapulco and Puerto Vallarta, could witness more bloodshed.

In smaller-scale operations in the past, the military has failed to firmly establish long-term control in areas run by cartels. Calderon's predecessor, Vicente Fox, sent the army into Nuevo Laredo in Tamaulipas state in June 2005 and to Acapulco in Guerrero state in early 2006 to restore order. In Nuevo Laredo, the army completely took over the city's corrupt police department, though the cartels were able to effectively resume their operations after a short time -- and the violence resumed. The military could yet experience some success in its Michoacan deployment, though the first day of operations -- which focused on burning crops at more than 100 marijuana and heroin plantations and searching cars at roadblocks -- netted just 13 arrests.

The military's ineffectiveness can be attributed not only to the sheer size of the problem, but to a great extent to corruption within the military and the government itself. The cartels are able to pay off military commanders or local officials to tip them off about impending raids or other operations. If the drug cartels have influence at the higher levels of Mexico's government and security forces, it is likely that the Michoacan operation will see federal troops taking aggressive action against some criminal groups, while others are left alone.

Calderon campaigned on a promise of controlling government corruption in Mexico, and followed up on that a week after taking office Dec. 1 by ordering federal police to raid the attorney general's office in Oaxaca state. This operation is his first major attempt to address the ongoing cycle of violence at the hands of the cartels.

Narcotics flow through Mexico like a river and, like rushing water, they will follow the path of least resistance. Placing a stone in one place will only make the flow divert around it -- if not wash right over it. In order to make a serious dent in organized crime, Calderon would have to conduct a wide-scale operation throughout the whole country, not just send troops to one state. By using a large force, by Mexican standards, Calderon could be trying to ensure his effort in Michoacan succeeds. Considering the strength of the cartels and the corruption at all levels of Mexican government, however, the operation likely will suffer the same fate as earlier ones.