This sounds like a story from the fever swamps, but it is confirmed by court documents.

The Drug Enforcement Agency had a secret arrangement with the notorious Sinaloa cartel "that allowed the organization to smuggle billions of dollars of drugs while Sinaloa provided information on rival cartels."

Business Insider:

Sinaloa, led by Joaquin "El Chapo" Guzman, supplies 80% of the drugs entering the Chicago area and has a presence in cities across the U.S.

There have long been allegations that Guzman, considered to be "the world's most powerful drug trafficker," coordinates with American authorities.

But the El Universal investigation is the first to publish court documents that include corroborating testimony from a DEA agent and a Justice Department official.

The written statements were made to the U.S. District Court in Chicago in relation to the arrest of Jesus Vicente Zambada-Niebla, the son of Sinaloa leader Ismael "El Mayo" Zambada and allegedly the Sinaloa cartel's "logistics coordinator."

Here's what DEA agent Manuel Castanon told the Chicago court:

"On March 17, 2009, I met for approximately 30 minutes in a hotel room in Mexico City with Vincente Zambada-Niebla and two other individuals - DEA agent David Herrod and a cooperating source [Sinaloa lawyer Loya Castro] with whom I had worked since 2005. ... I did all of the talking on behalf of [the] DEA."

A few hours later, Mexican Marines arrested Zambada-Niebla (a.k.a. "El Vicentillo") on charges of trafficking more than a billion dollars in cocaine and heroin. Castanon and three other agents then visited Zambada-Niebla in prison, where the Sinaloa officer "reiterated his desire to cooperate," according to Castanon.

El Universal, citing court documents, reports that DEA agents met with high-level Sinaloa officials more than 50 times since 2000.

[...]

"The DEA agents met with members of the cartel in Mexico to obtain information about their rivals and simultaneously built a network of informants who sign drug cooperation agreements, subject to results, to enable them to obtain future benefits, including cancellation of charges in the U.S.," reports El Universal, which also interviewed more than one hundred active and retired police officers as well as prisoners and experts.

Zambada-Niebla's lawyer claimed to the court that in the late 1990s, Castro struck a deal with U.S. agents in which Sinaloa would provide information about rival drug trafficking organizations while the U.S. would dismiss its case against the Sinaloa lawyer and refrain from interfering with Sinaloa drug trafficking activities or actively prosecuting Sinaloa leadership.

"The agents stated that this arrangement had been approved by high-ranking officials and federal prosecutors," Zambada-Niebla lawyer wrote.

This is hard-headed, cynical law enforcement; let some drugs in to keep more drugs out. But seeking out and negotiating an "arrangement" with these cold blooded monsters is sickening. We've seen how totally ruthless and barbaric their methods are and how they don't care if innocents are caught in the crossfire or not.

This information sheds further light on the Fast and Furious caper. Apparently, the DEA didn't care how many guns ended up in the hands of Sinaloa cartel members - didn't care who they killed, including border agents. They were only concerned about guns that ended up in rival cartel hands. The story validates reports from last August - totally ignored by most media - that Fast and Furious was meant as a program to supply arms to Sinaloa:

Ahigh-ranking member of the Sinaloa drug cartel operative currently in U.S. custody alleges that Operation Fast and Furious was part of an agreement to finance and arm the Sinaloa cartel in exchange for information used to take down rival cartels, according to court documents.

The statement was made by Jesus Vicente Zambada-Niebla, the Sinaloa cartel's "logistics coordinator" in charge of arranging massive drug shipments from Latin America to the United States as well as the son of cartel leader Ismael "Mayo" Zambada-Garcia and a close associate to kingpin Joaquin "El Chapo" Guzman.

Zambada-Niebla was arrested by Mexican authorities in March 2009 and extradited to Chicago to face drug trafficking charges.

From the court document:

[T]he United States government at its highest levels entered into agreements with cartel leaders to act as informants against rival cartels and received benefits in return, including, but not limited to, access to thousands of weapons which helped them continue their business of smuggling drugs into Chicago and throughout the United States, and to continue wreaking havoc on the citizens and law enforcement in Mexico.  

I could care less that we've been able to take down some drug kingpins from other cartels. The immorality of arming killers and allowing them to carry out their deadly business - which leads to hundreds of violent deaths in the US when gangs war on each other - is without question.

Who knew? Holder, obviously. He has been stonewalling Congress to keep his dirty little arrangement secret. That's got to stop. Holder and DEA leaders should be held accountable for the hundreds - perhaps thousands - of deaths that have resulted from our support of the Sinaloa cartel.

We've got blood on our hands and Holder helped put it there.