Answer: That buying war bonds will help prevent the Axis Powers fromtaking control of civilization.
Explanation: The Axis Powers is the alliance of Germany, Italy, and Japan during WW2. The grab represents the Axis Power's goals of taking over civilization and "grabbing it" for themselves. However the hand, represting the United States, is stopping this grab, representing that the United States will stop the Axis control of civilization. The cartoon states that using war bonds will help the United States get control of WW2, so therefore it's convincing citizens to buy war bonds so the US can stop German and Japanese spread of control.