The keyword "tyranny” in this poster is primarily used to

encourage viewers to feel sympathy for those who are forced to fight against such a hostile enemy.
convince viewers that winning the war will result in a restructuring of the enemy’s unfair political system.
inspire viewers to support the war effort by portraying the enemy as a cruel and unfair political force.
empower viewers to join the military by suggesting that the war can be won only if everyone joins the fight.