While I agree with the above posts, ultimately, the play focuses on the love of Romeo and Juliet and it ends with the resolution of the feud, even though the cost of the resolution is the death of the main characters. Young, foolish, misunderstood, or any other adjective you want to add here to describe them -- they are all true, but they do love each other enough to die for want of the other. Their love is central to the play's meaning.
What are Juliet's words when she discovers that Romeo is a Montague in Act I, Scene 5? "My only love sprung from my only hate!" Then, in Act III, Scene 1, there is again the confusion of love and hate when Romeo professes love for Tybalt since he has become Juliet's husband and Tybalt is a cousin; but, Tybalt does not understand and becomes incensed as he believes that Romeo insults him. Thus, Tybalt becomes even more enraged in his hatred to Romeo and his friend Mercutio, slaying the latter. Later still, in Scene 2, Juliet learns that Tybalt, her cousin, is dead having been killed by her husband Romeo. She again is crossed between these two strong passions of love and hate:
What storm is this that blows so contrary? Is Romeo slaught'red, and is Tybalt dead? My dear-lov'd cousin, and my dearer lord? Then, dreadful trumpet, sound the general doom!For who is living, if those two are gone? (3.2.67-71)
Apparently, therefore, the drama of Shakespeare's Romeo and Juliet is about the confusion of love and hatred since love originally out of hatred springs, which in turn reverts to hatred, then love re-emerges only to quell others' loves such as Paris's and manifest itself as hatred again. Finally, with Romeo and Juliet's deaths, acts of self-hatred born of love for the other, an end comes to the love/hatred relationships, and the Montagues and the Capulets resolve their animosity and live amicably after that. At this point, the reader may conclude that love and hatred are merely two sides of the coin of life.
I believe Romeo and Juliet is a play about both love and hate. Romeo and Juliet of course are madly in love. At the same time, both Romeo's and Juliet's families are in hatred of one another. I would argue, being I am an optimistic person as mentioned above, that the play is driven by Romeo's and Juliet's love for one another. The fact that their families hate one another is simply to say that Romeo and Juliet can never be together, except in secret. When I hear the words Romeo and Juliet, I automatically think of two young people so in love until hatred could not, would not keep them apart. In that view, love is the dominant theme. They lived to marry and love one another. They died in love one for the other.
I think that your answer to this is going to depend on what your outlook actually is. It might be a cop out, but I think it makes sense here. Perhaps, the answer to this question, then becomes reflected back on the individual. This is probably how Shakespeare would want it.
If a person basically has an optimistic or redemptive view of consciousness, then I think that they will see the play as a drama of love. Romeo and Juliet, two lovers, challenge their social order, their existing structure, and seek to embrace a world of what can be. It is in this where I think that the modern visage of West Side Story, and in particular the song, "There's a Place," really fits here. Both young people were able to see through the falsely constructed reality of their parents and envision a world for both of them, "a place" for their love and their hopes of the future. It is here where they both seek refuge, an arena for their hopes and dreams. In this, the play is one of love challenging the forces of hatred and negation.
The flip side could be argued, as well. If one believes that there is not redemption in consciousness, then I believe that the case is made that Romeo and Juliet end up dying because of hate. To a large extent, it is hate that is the constant element in the drama. It opens the drama, and while there is a promise to stop the intensity, it comes at the cost of the two young people from each house, their carcasses lying on the stage for all to see. In fact, it could be argued that hatred is such an element of the play because it forces them to embrace the other. If there was no antagonism between the families, the relationship does not possess that sense of subversiveness, which no doubt was an adrenalized factor for both of them. If the hatred between both families was not present, the relationship would not have possessed that quality of danger that excited and animated both lovers. The cost of hatred at the end of the drama is undeniable in terms of the death count that has been manufactured as a result of familial violence on familial violence.
One could go either way on this with both sides laid out in such a manner. I could only say that, in the end, one probably has to concede that there is a fluid relationship between love and hate in the play. The presence of one is constantly in flux and poised against another. Both of them are seen as necessary forces in the world, and we, as human beings, must learn how to navigate the demands between both in trying to answer the same questions that Romeo and Juliet had to encounter: Who am I and What shall I do?
Is th whole play about love or hate or both????????????