I suspect that cartels are moving to control new territory along the border, as barrier is being built in the previously most valuable stretches.
The three biggest corridors for illegal traffic - San Diego, the Rio Grande Valley and Yuma - will all be substantially closed by the end of next year, with Trump-style super barrier system. The cartels must prepare new routes, where the terrain allows.
The more than 200 mile unfenced gap along the Rio Grande in Texas, between Falcon Lake (South of Laredo) and Box Canyon (just North of Del Rio), is the biggest and best open stretch of border for smuggling left in Texas after the Rio Grande Valley gets closed off - arguably it will then be the best stretch of the whole US/Mexico border for illegal traffic, after the currently funded barrier building is finished (end of 2020).
52 miles of that stretch already has this year’s money budgeted against it (but that contract has not yet been awarded).
The attack described in this article, in Villa Union, Coahuila; is on the main highway leading to the Northern edge of where that barrier will run (52 miles running North from the Colombia Laredo Port of Entry).
This attack seems like a cartel (CDN) coming into a small town to take over. The big battles will erupt when cartels go against each other, for the biggest new routes.
When that happened before in Nuevo Laredo, the local police were disbanded an effective state of martial law persisted for years.
Government is tied to the cartel money...somehow some way break the reliance on cartel money