Retired U.S. Army Major General Paul Vallely's advice to POTUS on southern border, re: DOD vs. DHS roles, posted to his Facebook and twitter.

https://www.facebook.com/pv.nemo/posts/2197678547139955

https://twitter.com/paulvallely/status/1081964469289345024

https://en.wikipedia.org/wiki/Paul_E._Vallely