Mexico has exonerated a former defense minister who US prosecutors alleged was a drug capo nicknamed The Godfather, sparking outrage and claims that the country’s powerful armed forces have become untouchable. Gen Salvador Cienfuegos was arrested at a Los Angeles airport last October for allegedly shielding a multimillion-dollar conspiracy to smuggle drugs into the US. But those charges were dropped by the justice department in November as part of a controversial backroom deal and Cienfuegos returned home to Mexico. On Thursday night Mexico’s attorney general’s office announced it was completely absolving Cienfuegos, the defense chief under the former president Enrique Peña Nieto between 2012 and 2018. It claimed its investigators had found the 72-year-old general had neither met nor communicated with “any criminal group”. Mexico’s nationalist president, Andrés Manuel López Obrador, who is heavily reliant on the military, defended the move at one of his daily early morning press conferences on Friday. López Obrador, who is best known as Amlo, insisted his government opposed impunity and corruption – but nor were “retaliation” or “revenge” acceptable. “You can just invent crimes,” Amlo added, accusing the US Drug Enforcement Administration (DEA) of “fabricating” evidence against Cienfuegos. Those remarks will do little to calm anger over the general’s apparent escape from justice, both in Mexico and the US. Ernesto López Portillo, who runs the citizen security program at Mexico’s Ibero-American University, said the most troubling aspect of the saga was not the thought that the attorney general’s office might have given the green light to such impunity. “It’s the possibility that this impunity is the result of the armed forces imposing itself on the president himself. That is the most serious hypothesis of all,” López Portillo tweeted. Mike Vigil, the DEA’s former chief of international operations, told the Associated Press the decision “could be the straw that broke the camel’s back as far as US-Mexico cooperation in counter-drug activities”. Falko Ernst tweeted: “Holding the upper echelons of state power accountable is a necessary condition for breaking Mexico’s perpetual lethal conflict. Today cements a leap away from this.” Denise Dresser, a prominent political observer and government critic, tweeted: “Salvador Cienfuegos’s exoneration shows how the armed forces are untouchable, they are above the law … and will remain beyond democratic scrutiny.” Dresser claimed the exoneration suggested that the armed forces – which she called Mexico’s “new mafia in power” – are in fact governing Latin America’s number two economy. That was a clear reference to Amlo’s longstanding pledge to fight what he calls Mexico’s “mafia of power”. Mexico’s leader won a landslide election in 2018 promising to eradicate corruption and dismantle what he paints as Mexico’s hidden and dishonest elite. On Friday, Mexico’s president insisted he stood by those pledges. But Amlo acknowledged adversaries would use the exoneration “to attack us and convince people that we are all the same, that there has been no change, that we are cover-uppers and accomplices and tools of of vested interest groups and foreign governments”. The former DEA chief Vigil said the exoneration showed that “despite the political rhetoric of wanting to eliminate corruption, such is obviously not the case”. “The rule of law has been significantly violated,” he added.