Answer:
As Commander in Chief of the Army and Navy I have directed that all measures be taken for our defense.
Step-by-step explanation:
An appeal to ethos is a rhetorical strategy that an author employs in order to appeal to his credibility. When an author employs such a device, he presents the reasons why he is to be considered an authority in the matter. This appeal is designed to persuade the reader of the soundness and quality of the author's opinions. In this case, Roosevelt employs this strategy in order to highlight the fact that he is the Commander in Chief of the Army and Navy, and therefore, his opinion is a well-informed one.