FWIW:

U.S. and Mexican officials on Tuesday were investigating a bizarre encounter between Texas lawmen and heavily armed intruders who were wearing Mexican military uniforms while evidently escorting a caravan of sport utility vehicles that was smuggling marijuana into the United States.

The smugglers, spotted on the U.S. side of the border in remote western Texas on Monday afternoon, hastily fled back into Mexico, leaving behind nearly a half ton of marijuana and setting one of their vehicles ablaze...

Kristi M. Clemens, assistant commissioner for U.S. customs and border protection, issued a statement saying the agency is reviewing the confrontation and has asked the Mexican government for a "thorough investigation."

Oddly enough, I don't believe her.

Gov. Rick Perry has ordered an investigation into the episode.

"Whether indeed members of the Mexican military crossed into Texas, or they were thugs dressed up as Mexican military, the incident is unacceptable and troubling," said Perry spokeswoman Kathy Walt.

I'm slightly less skeptical of their investigation. Meanwhile:

A day after as many as 20 armed men in military fatigues crossed the Rio Grande into Texas before being chased back by U.S. authorities, the Mexican government ordered its troops not to come within 2 kilometers of the border.

While the Mexican Foreign Affairs Ministry and Defense Ministry denied their military had a role in providing protection for Monday's marijuana smuggling operation into Hudspeth County, the government said its military wouldn't be permitted in the border zone without authorization.

The face-off along the Rio Grande between the drug smugglers and U.S. law enforcement officials came just days after Mexican and U.S. officials downplayed news reports that U.S. Border Patrol agents have occasionally seen what appear to be Mexican army units in the United States.

"If it rattles like a snake and looks like a snake, it's probably a damn snake," Hudspeth County Sheriff Arvin West said. "There's no doubt it's Mexican military..."