This example of propaganda is an example of "testimonial," where a person essentially "testifies" in front of the viewer about his or her credible experiences in something, as the viewer can trust the person depicted. Captain Krench says so, so it must be true. In this case, Captain Krench "knows" something important and the viewer is drawn into believing what he says because the depiction makes him seem respectable, as a US military captain. His ethos, or credibility is increased, and he is connected with what the maker of the propaganda is trying to sell. And now, we see that it's not the government that is telling people what to do; they are employing real military men that more people trust.