Why didn't US officials who learned of Chapo's presence in Sonoita, Sonora, on Jan. 26, 2009, tell their Mexican counterparts?
According to a leaked document, the US authorities who suspected Chapo was there didn't say anything to their counterparts across the border. It reeks of conspiracy, keeping the Mexicans out of the loop on something like this. But it also reeks of reason and good judgment. According to a US Justice Dept. indictment, Chapo and his associates met for three days at a ranch in Sonoita. So first off, the US officials alerted someone higher up in their own chain of command, otherwise this never would have made into a federal indictmnt. Then there's the reason for Chapo's supposed meeting: after El Vicentillo's arrest, they were angling for revenge on the authorities. In Sonoita, they allegedly discussed the possibility of "orchestrating attacks against US or Mexican government buildings," according to the indictment. They were also allegedly plotting attacks in Mexico City – effectively, not Sinaloa cartel turf – in order to shift the authorities’ attention toward the Beltran Leyva brothers, who base some operations there.
What would have happened in officials in Arizona had alerted their local or state counterparts in Sonoita? Well, imagine the following scenario:
Arizona cop: Oye, compadres, I've got a tip for you. Chapo is apparently at a ranch just outside of your town.
Sonoita cop: Que bueno. Gracias for telling us. We'll go check it out.
Ending A: Local cops phone Chapo and tell him he's on the radar, and should leave town.
Ending B: Local cops actually try and raid the ranch, to become heroes. Their corpses are left at the roadside, accompanied by a message: Don't mess with us.
Either way, I wholeheartedly back the decision not to tell the Mexican cops anything in this instance.