Arrests, assassinations, and disappearances are a regular occurence in the drug trafficking world. With the tension between rival cartels at an all-time high in recent years, it seems that the powestructure among the various groups is always shifting.

Every group, from Sinaloa to Tijuana on down, the leaders are constantly changing face. It can be hard to keep track of who's in charge.

And now, with the capture of Sinaloa's "El Chapo" earlier this year, and the arrest of Tijuana's "El Ingeniero" during the Mexico-Croatia World Cup game this past week, it seems a good time for a cartel leader roundup.

Here are the most dangerous cartel leaders in the world -- for now, anyway.

Ismael Zambada-Garcia, or "El Mayo"

The partner of the captured Sinaloa leader "El Chapo," El Mayo is widely considered to be one of the most successful and most feared drug lords in the world.

Under the duo's reign, the Sinaloa Cartel dominated the market on cocaine market, and helped the massive group become a worldwide leader in methamphetamine, heroin and marijuana trafficking as well.

The dangerous thing about Zambada-Garcia is that he has no problem breaking alliances, as he's done many times over. A former farmer, the Sinaloa leader rose to power after his work with the Juarez cartel.

But when leader of the Juarez cartel Amado Carillo died in the '90s from botched plastic surgery, Zambada-Garcia saw his opportunity in the narco world and formed his own group. A number of divisions and alliances followed, and Zambada-Garcia ultimately ended up as one of the two leaders of the Sinaloa cartel.

Sinaloa cartel, the group Zambada-Garcia founded, is now the most powerful drug-trafficking, money laundering and organized crime syndicate in the world. They are responsible for the movement of nearly 200 tons of cocaine and heroin into the United States between 1990 and 2008, and have only gained power as the years have progressed.

Zambada-Garcia has funded a number of family businesses with the money from the narco-trafficking, and has been named one of the most successful -- and most wanted -- drug lords in the world.

A reward of up to $5 million dollars is being offered for information leading to his arrest.

Juan Jose Esparragoza-Moreno, or "El Azul"

As a former police detective, Esparragoza-Moreno knows a thing or two about how to evade detection by authorities. Perhaps that's why he's become one of the most dangerous, and surprisingly charismatic, leaders in the narco-trafficking world.

While other leaders on this list are considered dangerous due to their violent tendencies, it is Esparragoza's peacemaker personality that makes him as powerful as he is. He's able to talk his way into -- or out of -- just about anything, and has unified some of the smaller groups to heighten power and affix alliances.

Plastic surgery has made him unrecognizable at points, and he has evaded arrest by altering his appearance and building relationships with key people in charge -- politicians, authorities, and the like -- which has made him virtually untouchable.

He's an associate of El Mayo's, and is related to the work with the Sinaloa Cartel. A reward of up to $5 million dollars is being offered for information leading to his arrest.

Rafael Caro Quintero

Although he is considered a more recent threat on the narco-trafficking scene, Caro Quintero is actually quite the veteran drug trafficker. Founder of the now-defunct Guadalajara Cartel, Caro Quintero is considered the godfather of drug trafficking.

He was imprisoned in Mexico for trafficking, murder and abduction for the torture and murder of undercover DEA agent Enrique "Kiki" Camarena in 1989. But when a federal court overturned his sentence in August 2013 citing Caro Quinero's trial taking place in state court rather than federal, Caro Quintero was released from prison.

After Caro Quintero's release, the U.S. State Department offered a $5 million dollar reward for his arrest, and the Mexican Attorney General's office reissued an award for his arrest.

Caro Quintero has now been associated with the Sinaloa Cartel in the months since his release, but the extent or role of his influence is not yet known.

Juan Reyes Mejia-Gonzalez, or "El Quique" 

Juan Reyes Mejia-Gonzalez is a member of the Gulf Cartel faction "Los Rojos." The Gulf Cartel has been around since the 1930's, when they would smuggle whiskey into the U.S. during prohibition. They now control most of the cocaine and marijuana that flows into the U.S. through Matamoros, which borders on the Rio Grande Valley in south Texas.

Rumored to be associated with the violent torture and assassination of Samuel Flores Borrego, leader of the rival group Los Metros in 2011, the murder triggered a violent confrontation between the two groups. The confrontation is now believed to have shut down Los Metros with leader El Qique's murder, a fact with another narco group, Los Zetas, has confirmed.

Vincente Carillo Fuentes, or "El Viceroy"

El Viceroy is now the rumored leader of the Juarez Cartel after his brother Amado's death from a botched plastic surgery to change his appearance.

His retaliation against Sinaloa Cartel's incarcerated leader for the murder of his brother, in which he had El Chapo's brother assassinated outside of a movie theater, has only fueled the unrest between the border cartels.

Carillo Fuentes and the Juarez Cartel control one of the primary routes of transportation for illegal drug shipments to enter into the U.S. through El Paso, in which billions of dollars worth of narcotics are being funneled through annually.

El Viceroy became the center of attention with authorities after the notorious "House of Death" case came to light. The House of Death refers to a serial killing cite in Cuidad Juarez, Mexico, where members of the Juarez Cartel committed executions. A mass grave with at least 12 bodies of rivals was found in the house at the site.

Servando Gomez Martinez, or "La Tuta"

Known as "The Teacher" or "The Professor" for his past as a teacher, Servando Gomez Martinez is the leader of the Knights Templar Cartel in Michoacan. He is also the former leader and founder of La Familia Michoacana, a group whose split helped to form the Knights Templar Cartel.

The Knights Templar Cartel is one of the most dangerous and feared cartels in Mexico, moving tens of millions of dollars worth of illegal drugs into the U.S. as well as running prostitution rings, extortion rings, and human trafficking groups.

The Knights are labeled as a quasi-religious group, as they consider their murders of rivals to be "divine intervention." Gomez Martinez loves the publicity and limelight he receives for his role, and revels in the attention of interviewers and reporters.