Revenge
Revenge is the fuel at the core of the Capulet and Montague feud: when one side wrongs the other, the other retaliates with haste. This is evidenced in the opening scene when Sampson and Gregory antagonize Abraham into drawing his sword, instigating an all-out brawl, and also when Tybalt confronts Romeo as revenge for crashing the Capulet feast, which quickly turns into the most notable example of revenge in the story, when Romeo kills Tybalt to avenge Mercutio. This last example also shows that revenge is not only a toxic antagonist in the film, but a paramount plot device as well.
The Stars Being Connected to Fate
As mentioned elsewhere in this guide, the play's opening prologue famously calls Romeo and Juliet "star-crossed lovers," which is a reference to the belief that people's destinies were connected to the movement of the stars, and thus Romeo and Juliet's tragically forbidden relationship was a sign that they were marked by fate. This idea returns when Romeo hears of Juliet's death from Balthasar and shouts, "Then I defy you, stars!" which is an acknowledgement that he plans to intentionally go against what fate has in store for him—presumably to live a life without his love—by killing himself.
Excessive Passion
Romeo and Juliet is often regarded as an unrealistic example of passionate romance; however, closer observation reveals that this is in fact an intentional demonstration of the danger of reckless emotions and the characters who harbor them. Such emotions bubble up continuously throughout the story: the Capulet and Montague clans are both so quick to anger that they frequently terrorize the streets of Verona with violence; Lord Capulet is unable to contain his rage when Juliet won't marry Paris; and, of course, Romeo and Juliet fall so madly in love with each other that they're married within a day and dead within three. Voices of reason, such as those of Benvolio and Friar Lawrence, continually criticize the rash, impulsive dispositions of these characters, and this further highlights that the story does not exist in a world where heightened passions are more commonplace, but rather in reality, where they have real, dire consequences if not contained.
Life Cut Short
Premature deaths are the staple plot devices of Romeo and Juliet: we are told from the beginning that Romeo and Juliet are going to die to end their families' feud. Their relationship is even referred to as "death-marked love," and the solution to their parents' fighting as "their children's end." Moreover, we don't reach this tragic conclusion until Mercutio and Tybalt are also killed as a result of the infectious antagonism and anger that the feud promotes. Thus, lives being cut short is the fuel by which the entire plot operates, and is the ultimate example of the consequences of such unhealthy fighting.
Deception and Masquerading
Once Romeo and Juliet's torrid relationship begins, they and others go to great lengths to keep it hidden. The Nurse pretends to be heading to church to pray in order to speak with Romeo privately; Juliet uses her time for confession to sneak off to the chapel and marry Romeo, and later to beg the Friar for help. The entire affair even begins and ends with huge masquerades: first, Romeo pretends to be a party guest in order to gain access to the Capulet feast and eventually meet Juliet, and wears a mask when they first spot one another. Then, of course, their relationship meets its dark end when Juliet and the Friar create a ruse by which she appears to be dead. The common use of deception to further the story is another example of how the families' feud forces people into dishonesty and moral compromise, a demonstration of its ability to corrupt.
Society vs. Individuals
There are many examples of how Romeo and Juliet's relationship, and their ability to act autonomously within it, run up against institutional values and laws. Perhaps the most poignant example is their families' fanatical need to maintain their honor in the face of their enemies' challenges, a notion that conflicts with the children's desire to be with someone from the enemy side. The collective preservation of this honor stands in direct opposition to their romance. Juliet also runs up against the patriarchal norms typical of 16th century Italy, in which her father has the final say in who she chooses to marry; loving Romeo and refusing Paris' proposal is considered an act of defiance against him. The story's moral is a criticism of these institutional opponents and the problems they cause for two people who, had they been free to act independently, would not otherwise have faced such tragedy and hardship.
Them vs. Us
The feud between the Montagues and Capulets, an animosity that is unexplained but which is the pretext for the plot, is contingent upon the opposition between in-group and the out-group; in other words, the Capulets antagonize the Montagues simply for being Montagues rather than for doing anything wrong, and vice versa. Sometimes, their rivalry appears merely reflexive, without real hate behind it, as when Tybalt and Mercutio duel almost playfully, Mercutio making Tybalt laugh, and giving him back his sword so that they may continue fighting properly. Of course, as soon as things go amiss, the hatred returns with a vengeance.
The reason Romeo and Juliet are able to love one another unconditionally is because upon meeting they form a sort of new "group," comprising only the two of them, and creating a new trifecta: Them (the Capulets) vs. Them (the Montagues) vs. Us (the lovers). And it's this new allegiance only to one another that brings about all of their subsequent conflicts as they run up against the continued rivalry of the other two "Them"s.
