They are indeed building huge bunkers in large numbers

You sure as hell do when you put 80% of it outside your borders, outside US borders no less

This kind of thing could spark a war in different circumstances - imagine the Mexican army goes to dismantle the buoys in their borders, and one of several possible groups from Texas confronts them and it leads to a skirmish

Mexico would be entirely within their rights - it’s on their property and it’s suspected to be leading to deaths