Mexican law enforcement officials escort arrested members of the Sinaloa drug cartel in 2009. (Ronaldo Schemidt/AFP/Getty Images)

The Internet, and particularly left-leaning U.S. blogs, are abuzz with a story in the Mexican newspaper El Universal alleging that the United States cut secret deals with one of Mexico's largest drug cartels. The nature of those deals change based on which English-language version you're reading, but in the most extreme and widely circulated tellings, the U.S. allowed the Sinaloa cartel to "smuggle billions of dollars of drugs" and granted the organization "immunity and undisturbed drug trafficking" – even allowed it to "carry out its business unimpeded" (!!!) – in exchange for information on rival cartels.

It certainly sounds alarming. The Sinaloa cartel is one of Mexico's most powerful. It's a massive criminal enterprise with influence over vast stretches of territory and responsibility for a lot of mayhem within Mexico and extensive drug trafficking into the United States. The idea that the U.S. would make secret alliances with this organization would seem to confirm many of the worst perceptions about U.S. foreign policy and Washington's role in the world.

It's not clear, though, that the facts of the case bear this all out. Anything is possible. But, based on the information and analysis currently available, the story as it's being portrayed appears dubious. Here are several reasons why.

First, look at the sourcing. El Universal's investigation turned up lots of court documents that seem to confirm that the U.S. has maintained informants in the Sinaloa cartel and that those informants have given up information that helped the U.S. seize drugs, often from competing cartels. And that seems highly plausible.

Where the story gets a bit trickier concerns the allegations that the U.S. promised not to interfere with Sinaloa operations or to prosecute the cartel leadership. The sources for that claim are the defense attorneys of one Vicente Zambada-Niebla, a high-ranking Sinaloa officer (and son of the cartel boss) who was arrested in 2009. Zambada-Niebla had been working as an informant for the DEA; his lawyers claim that he'd cut this deal for near-cartel-wide immunity and hence cannot be imprisoned. Maybe you believe him or maybe you don't, but the evidence is thin and his claims just happen to serve the argument that he shouldn't go to jail for allegedly trafficking more than $1 billion dollars worth of cocaine and heroin.

Vicente Zambada Niebla, aka "El Vicentillo," is presented to the press by police after his 2009 arrest. (LUIS ACOSTA/AFP/Getty Images)

Second, Zambada-Niebla's own case seems to contradict his claims of a U.S. conspiracy. The Sinaloa member was arrested mere hours after meeting with DEA representatives, whom he was supplying with information. If U.S. officials had really struck this far-reaching deal with Sinaloa to tolerate its entire criminal enterprise, why would they allow the arrest one of their higher-placed sources in the organization? Zambada-Niebla's case does support the claims that the U.S. had informants within Sinaloa but not that it had bought those informants by allowing billions of dollars in unimpeded criminal enterprises.

Third, Zambada-Niebla has been locked up since 2009. It's been claimed that U.S. officials allowed unimpeded Sinaloa operations from 2000 to 2012 and that their coordination was at its peak from 2006 to 2012, but it's not clear how Zambada-Niebla would know about the organization's secret dealings after his arrest. More to the point, a number of stories about the revelations have winkingly pointed out that the alleged 2000-2012 deal coincided with a post-2006 rise in cartel activity, apparently suggesting that the U.S. bears direct responsibility for this. Again, it's not clear how Zambada-Niebla would be able to judge this behind-closed-doors cause-and-effect after his 2009 arrest.

Fourth, maintaining Sinaloa informants does not mean the U.S. is collaborating with that cartel. InSightCrime, which follows organized criminal activity in Latin America, posted an in-no-uncertain-terms rebuttal to the alarmist stories. (Hat tip here to analyst Dan Trombly, for sharing this link and his very helpful insights.)

"The detailed revelations show the US continues to work with criminal elements as part of antinarcotics efforts," writes Charles Parkinson of InSightCrime. "This is not some conspiracy to protect or favor certain groups -- it is a tactic employed by the DEA and other US agencies to allow them to focus efforts on priority targets, and allow them to build solid cases." In other words, picking up an informant in Sinaloa does not imply the U.S. gave it a green light to run drugs and sow mayhem across the Americas.

Fifth, being an informant for the U.S. doesn't give you carte blanche. That was obviously true for Zambada-Niebla, who was arrested within hours of chatting with the DEA. But, as Parkinson points out, the U.S. can still actively work against a cartel while juicing it for information – and that includes its own informants. He notes, for example, that the U.S. worked with rival Colombian cartel leaders when it wanted to go after Pablo Escobar in the early 1990s. After taking down Escobar, the U.S. turned its attention to the same cartel leaders that had ratted out Escobar, eventually capturing and imprisoning at least one of them. These are short-term, quid pro quo relationships, not lifelong amnesties or secret alliances, and everyone involved knows this.

So what does this all mean? What appears more likely is that U.S. law enforcement agencies have maintained informants within the Sinaloa cartel, offering to reduce or drop charges against cartel members in exchange for specific information on Mexican drug-trafficking operations. That's not so dissimilar from how U.S. law enforcement might, say, cut deals with informants in American crime organizations, offering them immunity or reduced sentences in exchange for information. It would also not necessarily be new, either, with respect to the U.S. efforts in Mexico. And there's every reason to suspect that the U.S. maintains, or will in the future maintain, similar informants in other cartels.

Whether or not that's a good strategy is certainly debatable. On the one hand, Mexican drug cartels are powerful ,and they're part of the landscape whether we like it or not, so if the U.S. can seize some major drug traffickers or actual drugs in exchange for reducing someone's sentence, that seems worthwhile. On the other hand, this seems to tacitly acknowledge that the cartels are part of the reality in Mexico now, which after years of fighting them is obviously pretty distasteful. But none of this necessarily means that the U.S. is actively taking the side of a Mexican drug cartel or allowing it to operate unimpeded.