MGMorden,
You say the placement of landmines violates international treaties. Foreign nationals (ie Mexicans) armed with automatic weapons crossing our border constitutes an act of war under international law, and I am certain violates any number of treaties; and by the way, those persons would not be protected under the Geneva Convention because they are not recognized enemy combatants. On that basis, placement of landmines at the national border is legal. Furthermore, if we placed the mines on OUR side of the border, there is absolutely nothing Mexico can say about it.
ST762