The motif of warfare
This novel belongs to the motif of war, because the story is one variation on a theme that is always nearby when war happens. War tears families apart. That's what it does. Both, because citizens enlist to fight abroad and are often lost in battle, but also because like this book reminds us, the effects of war are horrifying. In this book, the reader learns about infanticides that occurred, also kidnapping, brain-washing, and various types of horror. One could say this novel is about the cost of war.
Williams as a scapegoat
Not only is Eunice a scapegoat for her family (meaning that her real suffering also signifies the pain of her community), but also John Williams himself is literally used as a bargaining chip to free a French-Indian POW who was captured by the British—French Captain Jean Baptiste Guyon. That means that there is a question being raised about the worth of a human being. Williams himself feels that his children's lives are as valuable as his, but the Natives slay his children because they only see the value of him. He is forced to sacrifice just like Eunice does.
The reunion
To the actual people Stephen and Eunice, who knows what emotions really happened when they reunited as elderly people. In the book, the reader is given the impression that the reunion was difficult, but also heroic and victorious, because they were able to finally see some peace. One must understand that because of the historical importance of those battles, the family probably obsessed about that for years, and it became Stephen's obsession too. So the reunion symbolizes the final catharsis of years and years of struggle. Bittersweet, no doubt.
The English language
Language in this book symbolizes community, since that's what it provides human beings. When Eunice and her family discover that she no longer understands or speaks English, that is a symbolic reminder that technically (although the Williams family cringes to think about this), technically Eunice is in community with the Natives, whom the Williams family probably holds in contempt. This is a painful realization to them.
Love as a pursuit
Love is demonstrated as the relentless pursuit of Eunice's reunion to her family, even against horrific odds (these specific Natives are historically violent—they actually already killed two of Williams's children). So the sacrifice of bothering Native warlords for decades and decades is the sacrifice of pursuit and paranoia. The Williams family accepts whatever consequence comes as a result of their pestering, and they continue to pester the Natives until eventually, the Natives lose them.
