Brothers among Nations takes as its main theme the intercultural alliances made between Europeans and Native Americans in seventeenth-century North America. Although such interactions have been frequently studied in the wake of Richard White's influential book The Middle Ground, Brothers among Nations distinguishes itself by its wide-ranging coverage of the subject.

Van Zandt argues that for a period during the seventeenth century, from about 1620 to 1670, the fact that no single group along the Atlantic seaboard had decisive power meant that every group created and used a network of alliances in order to achieve their aims. This is not interpreted as a period of intercultural harmony; rather, it is argued that each side mistrusted the other and were forced into such relationships by their political circumstances, showing themselves happy to achieve their goals through warfare instead when possible.

The real value of Brothers among Nations lies in its geographical scope. By extending the area under scrutiny along the Atlantic coast rather than concentrating on any one colony or Native American group, Van Zandt is able to trace the ways in which apparently local alliances had far-reaching repercussions. She uses this wider viewpoint to find unexpected connections between events and decisions. Sometimes her subjects are familiar: for example, the part played by Pocahontas in the political relationship between Virginia and the Powhatan. But even much-studied examples are given an interesting twist. In a chapter on Plymouth, Van Zandt argues that Bradford's famous account has misled historians into believing that Puritan colonists disapproved of all intercultural alliances. She counters this by examining the career of the merchant Isaac Allerton, whose success was due to his ability to negotiate and trade with a variety of groups; this versatility did not prevent him from being a respected member of the church and community at Plymouth. Other chapters explore less familiar relationships. An alliance between the Susquehannock and an English trader, Captain Claiborne, is shown to have had lasting consequences in the early settlement of Maryland. Links forged within Manhattan's diaspora African community enabled slaves to put pressure on the Dutch East India Company, through a combination of community solidarity and exploitation of the Dutch fear of external attack. Finally, two apparently unconnected events in 1655 – the Dutch conquest of New Sweden and the Peach War – are shown to be linked. By tracing the complex networks of local alliances and enmities, Van Zandt explains the participation of the Susquehannock in both events through their patronage of the vulnerable Swedish settlement.

The greatest disappointment with Brothers among Nations is related to a preliminary chapter, which discusses the ways that maps and mapping became integrated into European culture and exploration in the sixteenth century. In itself this chapter is fascinating, but it never seems fully developed, or entirely integrated into the rest of the book. Despite this, however, Brothers among Nations is an interesting and useful study which throws new light on the period by revealing a wide-ranging web of relationships along the seventeenth-century Atlantic seaboard.