Particularly troubling was Trump's dawdling on ambassadorships after he created a problem by firing every current ambassador the moment he took his oath. While he had the power to do so, traditionally incoming presidents leave sitting ambassadors, especially career diplomats, in place until the Senate confirms their replacements. That ensures a steady flow of information and assures foreign leaders about continuity between administrations.
After more than seven months in office Trump had nominated only 36 of 188 ambassadors.
This meant that in foreign capitals when multibillion-dollar investment decisions were being discussed, political intrigues were unfolding, and informal changes in policy were under way, the United States often had no one with authority at the dinner tables, cocktail parties, or official government proceedings where they could pick up intelligence. Just knowing who sat where, or who was absent, at functions often provides valuable insights into foreign affairs. Not having ambassador-rank representatives on the scene posed serious economic and national security risks to the United States and was not consistent with Trump's claims that he would always put America first.
The failure to promptly fill these positions, and many others, raised more than the issue of Trump's lackadaisical approach to governing and ignoring basic duties while he spent hours watching television to learn what was being said about him.
His neglect also brought into question whether he was Violating his oath to "faithfully execute" the duties of his office as Article II, Section 2 of the American Constitution clearly states.
The Constitution does not employ the discretionary verb MAY or the merely authorizing word CAN, but a verb that imposes a duty to act. And it uses that mandating verb twice: "he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law."
Another big reason for the slowness in filling important posts is Trump's mercurial nature and how it creates unnecessary problems. Instead of thoughtful, even calculated, official actions, Trump's volatile emotions often drive his decisions. So does whatever he heard from the last person he spoke to. So one of the first things General John Kelly did as White House chief of staff was to control who sees the president and what papers they put in front of him.
David Cay Johnston "It's Even Worse Than You Think: What the Trump Administration Is Doing to America" 2017
