I find this headline and, in fact the article; misleading.
There was an article covering the President of Mexico's point of view, over the past week and half; that hasn't been given much posting time or commentary - and it made this particular move by President Trump predictable, in my view:
The President of Mexico was correctly pointing out, that conspirators in the US, who supported open borders and represented drug interests; were in a symbiotic relationship with cartels. Think about it...cartels are fulfilling a business need for some group of domestic business people in the US; otherwise, their business model of human trafficking, drugs and illegal infiltration wouldn't be thriving. I know that its abhorrent to think of US interests running these as business; but they are - albeit illegal ones.
We saw this most recently with the head of Portland (OR) Antifa, who had entered a business agreement with the attorney of one of the Cartels several months ago; promising to supply the cartel with arms; if the cartel trained Portland Antifa members in assault tactics. Their original targets were going to be the Border Patrol. It was squashed and the Portland Antifa head is now under Federal Custody.
And this is just one incident: I'm certain there are more that haven't come to light.
You see, as long as powerful political and Chamber of Commerce business interests in the US also support an open borders ideological model; cartels will have a thriving business model themselves. And fulfilling this need for cheap labor; keeps the borders open, for all manner of other illegal activity. Since Trump hasn't made enough in-roads to shut this supply line down - from all angles - then it wouldn't be possible to enforce this declaration.
Clearly, this joint Mexico-US border issue needs to be seriously addressed from both sides of the border. But set anyone up for failure; only to emboldens the cartels - and the deep state, by the way.
Its more prudent to continue to squeeze this business model to extinction, progressively - from all angles. And we do that by elections of closed border supporting conservatives.
Elections, from local to national levels; have consequences. And its time to throw the riff-raff out, in 2020.