Answer:
This poster appeals to the viewer's fear of the enemy which is clear through the large warning at the top of the page in bold, intimidating letters spelling out "Beware", as well as a depiction of what looks like Hitler looming above the American soldiers with his hand to his ear, listening for them to slip up and reveal vital information. It also appeals to a sense of pride and patriotism for the American soldier by encouraging him to "Do [his] part in silence", implying that the soldier owes this service of discretion and caution to his country.
Step-by-step explanation: