Yes, I was referring to the "unauthorized incursions".
They also enter for training. It happens often in Arizona.
At Ft. Huachuca? Davis-Monthan? Luke? South Tucson? The Rodeo Parade?(Just kidding).
I have never heard of or seen any Mexican Army units in Arizona for training. I have seen individuals there, but never a unit, never a truck or any thing else. Would love to hear details.