The Fall of El Mencho and Its Aftermath in Mexican Organized Crime

There are only a handful of names that have had a lasting impact in the history of Mexican organised crime. Nemesio Oseguera Cervantes – more commonly known as "El Mencho" – is one of them. Hailing from humble rural roots in the western state of Michoacán, his rise to the top of one of the most feared and dangerous cartels in modern Mexico, the Jalisco New Generation Cartel (CJNG), was meteoric. And it was achieved through aggression, ambition, brutality and ruthlessness.

His killing has been heralded as a victory in both Mexico and the United States. The Mexican authorities and the US reported that US intelligence was involved in bringing down the kingpin, lending the operation a sense of cross-border co-operation that could benefit both governments. For the Mexican military, a cartel leader has been removed from the equation, thereby weakens – at least in theory, and maybe for a time – the criminal group he ran.

The response from El Mencho's men has been swift. Roadblocks have been erected and violence has spilt over into the streets in as many as eight different states, from Guerrero on the Pacific coast to Tamaulipas in the north-east. Even the capital, Mexico City, and the surrounding Mexico State have seen incidents. Some of the worst violence has been in Jalisco itself, with masked gunmen setting fire to stores in the state capital, Guadalajara – one of the venues for this summer's Fifa World Cup. In the beach resort of Puerto Vallarta, tourists and locals alike are sheltering in place until the wave of violence passes.

It's a show of loyalty from El Mencho's foot-soldiers and a show of fury at the authorities for eliminating their leader. But whether the roadblocks and burning cars are for anything more than just show – that is, whether the violence de-escalates or ramps up – will only become clear over next few days. The reaction by law enforcement will be critical in that regard.

It is a long-held truth about such transnational criminal groups that, even with a cartel head as influential as Oseguera, there are inevitably three or four well-placed lieutenants on hand to replace him. Undoubtedly, though, El Mencho was key to the group's ascendancy. When he moved to the US as an undocumented immigrant in the 1980s, he had already had his first brushes with criminality in cultivating the marijuana fields of his native state. Various arrests in the US followed as he dug deeper into narcotics crime in California, before eventually being sentenced to several years in prison in the US.

Oseguera was deported back to Mexico aged 30 and began to fully immerse himself in cartel activity. He worked for the Milenio Cartel, based out of his native Michoacán, and grew in stature and reputation as a calculating and cruel boss. He was ideally placed when the cartel fractured and, from its remnants, the CJNG sprang up with El Mencho at its head. Through a combination of territorial expansion and the nimbleness to pivot the cartel's activity into new and lucrative illegal activities, he turned the group into what it has become today – arguably the predominant criminal force in Mexico.

His leadership and his cartel benefitted from the collapse of the Sinaloa Cartel after the extradition of its leader, Joaquín "El Chapo" Guzmán, to the US. Subsequent battles between warring factions in Sinaloa have ultimately torn the group apart. The New Generation Cartel was on hand to hoover up an important portion of the fentanyl trade after the fall of El Chapo's sons. One of them, Joaquín Guzmán López, handed himself in to the US authorities and brought down his group's biggest rival, Ismael "El Mayo" Zambada, with him. El Mencho was a clear beneficiary of the vacuum and the dramatic sequence of events in Sinaloa. But, as is so often the case in Mexican drug crime, it was not a crown he wore for long.

The government of Mexico's President Claudia Sheinbaum will portray the removal of one of the country's most wanted men as a victory and this will be echoed in Washington. It shows progress on the main issue from which US President Donald Trump has demanded action from Mexico after immigration: fentanyl trafficking. Given the element of US intelligence apparently involved, it also underlines the Sheinbaum administration's willingness to work together with Washington in pursuit of the same goals.

She would hope it will be enough to stave off any further talk of the need for unilateral US military action on Mexican soil in the form of drone strikes or boots on the ground – something which some in the Republican Party and in the Trump administration have openly called for. Such discussions are still to come. For the time being, Mexicans are still processing that El Mencho is dead, and in his absence watching cartel members set fires in the streets in cities across the nation.