The context of our commitment to nato. >> are you among those who thought it was catastrophic and a huge error for donald trump not to explicitly endorse article 5 when he was at the memorial? >> i do, both because of the situation where he found himself next to the 9/11 memorial which, after all, was the 9/11 attacks was the first and only time that nato invoked article five, the collective defense provision of the treaty. also during the campaign, he had says things about nato, he called it obsolete and not necessary. there was an expectation on the part of his aides and everybody else that ...