What is the purpose of the two metaphors Kennedy uses in the phrase: "If a beachhead of cooperation may push back the jungle of suspicion..." (paragraph 20)?

A.) Kennedy uses the metaphors to emphasize that just like in World War II, the United States just establish a beachhead in order to attack its enemies.
B.) Kennedy uses the metaphors to conclude his argument that the U.S. and its adversaries must cooperate and reject their suspicions of each other.
C.) Kennedy uses the metaphors to explain that the new generation must be willing to face the global issues that will define the future.
D.) Kennedy uses the metaphors to argue that the U.S. and its adversaries must quit being suspicious of the jungle if they are going to successfully cooperate.