Last week’s arrests of three generals and a lieutenant colonel in Mexico has fueled widespread speculation over the factors at play behind the detentions, and their implications for the country's changing political and criminal landscapes.

The arrests that began with General Tomas Angeles (see photo), a former undersecretary of defense, last week have now resulted in three generals and a lieutenant colonel being placed under "arraigo" (a preliminary detention in which criminal behavior is investigated without charges being filed) for 40 days. The military officials all stand accused of working for the Beltran Leyva Organization and their allies. People subjected to the arraigo are often charged at the end of the period, but it is not a foregone conclusion; in many prominent cases, the subject of the investigation has also been cleared.

As Animal Politico reported, the accusations stem, at least in part, from the testimony of Edgar Valdez Villarreal, who went by the moniker La Barbie, who turned himself into authorities in August 2010. While drug traffickers have a clear incentive to corrupt military officials, the allegations of extensive links between the military and the BLO are a bit counterintuitive; Arturo Beltran Leyva, the group’s boss until his death in December 2009, was killed in a shootout with military forces, and his brother Alfredo was arrested by the army in January 2008. If this gang was paying millions for support from the highest levels of the army, the bribes ultimately bought them very little.

Valdez Villarreal reportedly enjoyed a turbulent relationship with Arturo Beltran Leyva, his apparent boss. According to the account that Valdez Villarreal gave to authorities following his arrest, when faced with the military assault that would ultimately end his life, Beltran Leyva called Valdez Villarreal for help, which the latter was unable to provide. Instead, Valdez Villarreal urged him to surrender.

Previous investigations have already demonstrated substantial links between the BLO and government officials. The most notorious examples were revealed in 2008’s Operacion Limpieza, or Operation Clean-up, a massive investigation which uncovered a BLO mole working in the US embassy, as well as payments of several hundred thousand dollars to a Mexican former drug czar.

The recent arrests are somewhat surprising, however, considering the BLO's decline in recent years. The drug gang rose to prominence in the 2000s as part of the Sinaloa Cartel, but split with the group after the arrest of Alfredo Beltran Levya in 2008. (Arturo blamed Sinaloa boss Joaquin ‘El Chapo’ Guzman for his brother’s incarceration.) Following the split, the BLO suffered a series of severe blows, birthed a number of splinter groups, and was reduced to a seeming shell of its former self, under the leadership of Hector Beltran Leyva.

But while the organization may be less influential than before, these arrests make clear that the gang has not disappeared. Earlier this month a group linked to the BLO engaged in a significant firefight in the Sierra Madre region of Sinaloa, a region that is typically described as controlled by the Sinaloa Cartel. The BLO has also turned into a key ally of the Zetas and the Juarez Cartel, and has continued to post mantas taunting Guzman in the Sinaloan city of Guasave ever since the split. In short, weakened though it may be, the BLO seems unlikely to disappear.

While the high profile arrests sparked a great deal of interest, the lack of clarity regarding the allegations have led to an enormous amount of theorizing and speculation. One explanation points to the July presidential election as a key factor, and posits that the arrests stem from the officials being close to the Institutional Revolutionary Party (PRI). According to this theory --which points to a recent appearance by Angeles at an event by a PRI-affiliated think tank as evidence, though there is little else to support it-- rival National Action Party (PAN) officials ahead of a likely PRI victory this summer, are looking to reduce the influence of the generals most hostile to their party. Adding to the appeal of this theory is the fact that Angeles greeted presidential frontrunner Enrique Peña Nieto at the event, and has reportedly advised Peña Nieto's campaign on matters related to public security.

Others have said that the investigations could be the product of the BLO’s enemies --namely, the Sinaloa Cartel-- filtering information to their own connections in the government. That way, even if the allegations cannot be proven, high-ranking officials perceived as unfavorable to Guzman and his organization are essentially removed from any future shortlist of influential Defense Department appointments.

Beyond the theories, these arrests undeniably diminish the patina of military cleanliness and honesty that have long persisted in Mexico. Poll after poll has shown that the military, compared to the disdain reserved for the nation’s various police bodies, is seen as one of the most reliable and respected institutions in Mexico. Indeed, this was a primary justification for Calderon having relied so heavily on the armed forces; the military may not be an ideal domestic police organization, but an imperfect yet honest force was deemed far better than a police force riven with corruption.

While the arrests of Angeles and his fellow officers don’t disprove that hypothesis, they do reveal it to be woefully simplistic. Moreover, the past week demonstrates that no institution is immune to organized crime’s corrupting power.