With Treviño's capture, several scenarios could enfold.
His brother could take over, but Campbell, Hope and the geopolitical intelligence firm, Stratfor, all question whether he has the respect or capabilities to head a national criminal outfit.
"I wouldn't bet on that," Hope said.
More violent prospects include the Sinaloa and Gulf cartels attacking Los Zetas in Northern Mexico in a bid to control Nuevo Laredo, "the crown jewel for cross-border flows for goods, services, guns, money, drugs and illegal aliens," Grayson said. Also, the professor postulated the Gulf Cartel could move to take over the Matamoros and Reynosa border crossings.
Another possibility is that the small gangs helping to fill out Los Zetas' ranks could begin operating independently or be absorbed by other cartels, several experts said. This would be similar to what happened after Colombia broke up the Medellin and Cali cartels.
" 'Cartelitos' emerged that were violent and successful in shipping cocaine, but did not pose a threat to the nation-state," Grayson said.
Whatever happens, don't expect much impact on the U.S. side of the border, said author Charles Bowden, whose books on the Mexican drug war include "Murder City: Ciudad Juarez and the Global Economy's New Killing Fields."
"His arrest means nothing," Bowden said. "None of the arrests under (former President Felipe) Calderon affected the shipment of drugs to the U.S. or the price of drugs in the U.S."
Added Hope, "To affect the volume of drugs going into the U.S., there needs to be a reduction in the demand for drugs in the U.S."