At a January meeting, Trump "disregarded the significance" of the U.S. military presence on the Korean Peninsula, Woodward writes. Mattis was alarmed, telling close associates Trump acted like — and had the understanding of — 'a fifth- or sixth-grader.

At a January meeting, Trump "disregarded the significance" of the U.S. military presence on the Korean Peninsula, Woodward writes.

Mattis was alarmed, telling close associates Trump acted like — and had the understanding of — 'a fifth- or sixth-grader.'https://t.co/ixipn1Ofq9

— Kyle Griffin (@kylegriffin1) September 4, 2018