If I recall correctly, last year the nation of Mexico threatened the "Minuteman Project" with a lawsuit in U.S. federal court for impeding the flow of people (illegal immigrants) into the United States. And more recently, that Mexico has threatened to drag the United States government before the United Nations over the declared intention to build 700 miles of border fencing to, again, slow the flood tide of "illegal aliens" coming across the U.S. southern border.
I guess that somewhere in my 50-plus years of life, seven years of college, two degrees and a lifelong study of our nation's history, I must have gotten it all wrong. I've always thought the United States was a sovereign nation, one that had the right to protect its borders from illegal entry. One that was governed by the principles of a representative republic with a democratically elected government.
Apparently the United States, and all of its heretofore internationally recognized rights, doesn't "really" exist -- at least in the mind of the Mexican government.