This doesn't sound like much but if you look on a map, Trump is making the entire Mexican border of California, Arizona and New Mexico into a 60-foot-wide military base. (Map in second link.)
www.foxnews.com

Trump orders military to take control of federal land at southern border
President Trump in a memorandum Friday ordered the military to take control of a strip of federal land along the Southern border that would be designated "National Defense Areas."
MSN
www.msn.com