Death and destruction.
Gunfire, explosions, and casualties.
they were used to spark protest against America's involvement in the Vietnam War
This is a purely subjective observation: most of the Vietnam War era media illustrations I've seen appear to depict the futility of that conflict, in one way or another.
The media in Vietnam was drawn to photography depicting action. Ask any video game player today...action sells!
What readers like to see...action (blood and gore).
The new "Helicopter" war.
No that is the name given to hand drawn illustrations before the printing press. The illustrations of medieval codices were known as illuminations, and were individually hand drawn and painted. With the invention of the printing press during the 15th century, books became more widely distributed, often illustrated with woodcuts. - Wikipedia
Laos and Cambodia were both drawn into the Vietnam War because of atrocities the people of these two countries suffered under the hands of North Vietnam. South Vietnam and other countries were trying to keep the North Vietnamese army from spreading Communism in these countries.
Mainly horse drawn carriages then to diesel trucks.
Tried to get the South Vietnamese to defend themselves.
Illustrations are visual representations created to enhance or clarify a concept, story, or idea. Pictures are two-dimensional representations of a scene or object usually captured through photography or drawn images. Both serve as visual aids to convey information or emotions.