Very well written! I liked this book. It was one of the better assigned-reading books I have had. There are a few things that could be smoothed a tad. Here are some thoughts:
they are forced into a loveless marriage
Yes, the women are married to the same man. At the same time even. Coming from a western mindset, the women being forced into a loveless marriage makes it sound like they are marrying each other. I think you need to clarify here. You could say that they are forced into a loveless polygamous marriage, they are forced into loveless marriages, or some other construction that doesn't make it sound like they are in a same-sex union.
In Khaled Hosseini's A Thousand Splendid Suns, the tragic theme of oppressed hope is explored as the lives of Miriam and Laila pan out from childhood to death. Through the many obstacles that are thrown at these women, the hopes that they hold onto are constantly shattered.
This construction isn't wrong, but I thought I would point it out because it is my English teacher's biggest pet peeve. He can't stand it when students use a "to be" verb and then a past participle (and "ed" verb). Hopefully, you have an English teacher that is a little more reasonable. Hosseini explores the tragic theme ... The many obstacles thrown at these women shatters the hopes ...
Hope for acceptance, love, and a better life are among many things that the women of Afghanistan hope in the backdrop of war and danger.
Because this isn't an essay on the women of Afghanistan, but the lives of the Afghan women in the novel, I'd change the wording to reflect what the reader can expect in the paragraphs to come. I feel like there is a preposition missing. "Hope in" and "in the backdrop of war" blends together and I don't know where to mentally put the "in" when I am reading it.
Ack! I just looked at the time. I have got to get my own homework done and get to bed. Here are a couple more quick thoughts though:
Miriam has a miscarriage during pregnancy
Miscarriage and pregnancy are redundant because you can't have a miscarriage if you are not pregnant (unless it is a miscarriage of justice, but I digress). Punch up those verbs a bit by rewriting it something like this: Miriam suffers a miscarriage.
Nana is like many women, and hope that Jalil convinces his wives to marry her and support Miriam.
Again, it sounds like the wives will be the ones marrying Nana. "Hope" belongs with Nana--Nana hopes.
The book, A Thousand Splendid Suns, is riddled with oppressed hope of the women and children to the people of Afghanistan and the unstable politics that is occurring at that time.
Because you haven't developed the oppression of the children or the other people in the body of the essay, I wouldn't bring it up in the conclusion. "The unstable politics that is occurring at that time" is awkward. I'd simplify it to "the unstable politics of the time."