The people responsible for this should be fired.

Immediately.
Sheriff Larry Dever of Cochise County, Ariz., one of four Arizona counties contiguous with the U.S-Mexico border, said Friday that the U.S. Border Patrol has pulled back from parts of the border in his and neighboring counties because manning those areas has become too dangerous.
...
Dever stressed that the Border Patrolmen are ready and willing to perform their mission of securing the border, but that Border Patrol managers had determined that in “some places” the danger was too great and they wanted to avoid the risk of an international incident such as a cross-border firefight.
If the bastards are crossing our border, and shoot at our guys, the action needed is to do something about it, you morons, NOT GIVE THEM FREE REIN IN THE AREA! And if Mexico doesn't like it that a bad guy gets shot while shooting into the US, screw Mexico; tell them to do something about the bad guys on their side so our guys don't HAVE to worry about shooting back over the effing border.