The NBC presidential forum on Wednesday night in Manhattan brought together the candidates Hillary Clinton and Donald J. Trump to try to determine who has the strength, preparation and presence of mind to lead during a time of crisis.

It sure wasn’t Matt Lauer.

In an event aboard the decommissioned aircraft carrier Intrepid, the “Today” host was lost at sea. Seemingly unprepared on military and foreign policy specifics, he performed like a soldier sent on a mission without ammunition, beginning with a disorganized offensive, ending in a humiliating retreat.

Mr. Lauer interviewed the candidates in turn for a half-hour each. He began by asking Mrs. Clinton to defend her use of a private email server as secretary of state. And asking again. And again.

Roughly a third of his questioning dealt with the emails — a matter certainly connected to national security, but also a staple issue of this year’s campaign-trail reporting. It suggested, as the rest of the forum confirmed, that Mr. Lauer was steadiest handling issues familiar to anyone with a passing knowledge of the morning politics headlines.