Acting Sec. of Defense Pat Shanahan said the Pentagon was trying to determine how long US troops would be required to support security on the southern border, saying, "We really need to get back to our primary missions and continue to generate readiness" https://t.co/0jOLBkeNsc https://t.co/EvyF9BF7mK

Acting Sec. of Defense Pat Shanahan said the Pentagon was trying to determine how long US troops would be required to support security on the southern border, saying, "We really need to get back to our primary missions and continue to generate readiness" https://t.co/0jOLBkeNsc https://t.co/EvyF9BF7mK (via Twitter http://twitter.com/CNN/status/1123956516141375490)