The Yale Law Journal

June 2022

Navassa: Property, Sovereignty, and the Law of the Territories

U.S. Territories

abstract. The United States acquired its first overseas territory—Navassa Island, near Haiti—by conceptualizing it as a kind of property to be owned, rather than a piece of sovereign territory to be governed. The story of Navassa shows how competing conceptions of property and sovereignty are an important and underappreciated part of the law of the territories—a story that continued fifty years later in the Insular Cases, which described Puerto Rico as “belonging to” but not “part of” the United States.

Contemporary scholars are drawn to the sovereignty framework and the public-law tools that come along with it: arguments about rights and citizenship geared to show that the territories should be recognized as “part of” the United States. But it would be a mistake to completely reject the language and tools of property and private law, which can also play a role in dismantling the colonial structure—so long as it is clear that the relevant entitlements lie with the people of the territories. Doing so can help conceptualize the harms of colonialism in different ways (not only conquest, but unjust enrichment), and can facilitate the creation of concrete solutions like negotiated economic settlements, litigation against colonial powers, and the possibility of auctions for sovereign control.

authors. Faculty at the law schools of Duke University and the University of Virginia, respectively. For conversations about this topic, we thank David Billington, Chris Buccafusco, Guy Charles, Jacqueline Charles, Justin Desautels-Stein, Gio Fumei, Ira Kurzban, Christina Ponsa-Kraus, and Mark Weidemaier. The editors of the Yale Law Journal, especially Ethan Fairbanks, Alexis Kallen, Rekha Kennedy, Danny Li, and Bo Malin-Mayor, provided excellent suggestions.


The U.S. territories and the concepts with which scholars, judges, and lawyers address them are suspended in a netherworld: the unincorporated territories “belong[] to” but are not “part of” the United States, as the Supreme Court held in the Insular Cases.1 This legal no man’s land has continuing consequences for the millions of Americans living in the territories, and it also presents fundamental challenges for those attempting to understand, let alone unwind, the United States’s colonial legacy.2 What are the territories? The contemporary debate proceeds in the language of public law, but federal authority over the territories derives from the Property Clause.3 What role might private law play in resolving their status?

In this Article, we show how the present state of affairs is partially traceable to confusion and manipulation of the concepts of property (“belonging to”) and sovereignty (“part of”), and that each has a potentially important role to play going forward. The trajectory of debate about the territories’ status has moved from the former conception to the latter, and for understandable reasons. Nations historically used property concepts to justify conquest while avoiding the duties and obligations of governance, as the case of the U.S. territories painfully illustrates.4 The contemporary question is thus seen as one of public law and governance, as are the suggested remedies: arguments about citizenship, rights, and sovereignty. These arguments are powerful and essential, but incomplete, because the property framework also contains tools that can help clarify and resolve the territories’ legal status. The challenge therefore is not to reject the tools of property—concepts like ownership, economic incentive, transfer, and payment—but to reforge them for the tasks at hand: self-determination, economic justice, negotiation, and reparations.

Sovereignty and property are among the most contested and ambiguous terms in legal thought, and we do not purport to offer new or certain definitions of them here. But we do think that they invoke different broad families of concepts, generally tracking the distinction—again, blurry and contestable—between public and private law. As Martti Koskenniemi puts it, “Sovereignty and property form a typical pair of legal opposites that while apparently mutually exclusive and mutually delimiting, also completely depend on each other. Their relationship greatly resembles the equally familiar contrast between the ‘public’ and the ‘private,’ or ‘public law’ and ‘private law.’”5 The division between private and public law, in turn, can generally be thought of as “a naturalized law of things on the one side and a politicized law of power on the other.”6 Broadly speaking, our argument is that the law of the territories—not unlike, say, takings law7 or the debate over reparations8—rewards close consideration of both public- and private-law concepts. The language of property, for example, can help recognize and even remedy political and social phenomena that might not immediately register as private-law issues.9 As we see it, the argument that a territory is entitled to statehood resonates in public law;10 an argument that damages are owed for the wrongful taking of a territory, however, might resonate more in private-law concepts like restitution and unjust enrichment.11

To illustrate the significance of the property and sovereignty frameworks and set the stage for evaluating them, we begin with the story of a single overseas territory—the oldest of all the U.S. territories,12 and in that sense the place where the story of U.S. imperialism began: Navassa,13 a sunbaked and uninhabitable rock buried under a million tons of bird droppings, and located roughly forty miles from Haiti,14 which also claims the island.15 Beginning with an unoccupied and seemingly minor territory helps us isolate and grasp conceptual threads that run through the treatment of inhabited territories like Puerto Rico. Pulling on those threads can unravel a lot of colonial fabric.

The United States acquired Navassa in 1857, pursuant to the Guano Islands Act,16 which gave the President power to recognize as appurtenances to the United States any islands discovered and mined for guano by U.S. citizens.17 The Act also explicitly provided that the United States need not retain the islands once mining was
complete.18 The underlying framework was in that sense one familiar to property law: the incentive structure was commercial, the mode of acquisition was Lockean,19 and nothing in the Act committed the United States to actually govern the islands. This approach might be contrasted with a sovereignty-type framework in which new territory becomes part of a nation-state whose borders are insulated from change.20 In fact, the United States, like many imperial powers at the time, often explicitly resisted sovereignty—in part because of the obligations that it might entail.21

The story of Navassa is thus in part a story of a colonial power using the concepts of property and sovereignty to its advantage, and thereby relegating the island—like Puerto Rico and the other unincorporated territories—to the status of a “disembodied shade.”22 But even as the dust was settling on the Insular Cases and the United States was fighting a war over the status of its largest territory (the Philippines), U.S. legal scholars were exploring—and complicating—the conceptual relationship between property and sovereignty.23 That ongoing exploration and the law of the territories have much to learn from each other.

Contemporaneously, international law was moving away from the property framework, making it incumbent upon colonial powers to treat their territories as something other than possessions to be conquered, exploited, or bartered for economic gain.24 By the middle of the nineteenth century, this development, combined with the rise of the principle of self-determination, helped precipitate a wave of decolonization worldwide.25

But shifting to a public-law frame that treats sovereignty as both an obligation and a given obscures other possible solutions. Governance arrangements became more a product of status than of contract.26 This reification of sovereign territory is an implication of territorial sovereignty, and—with limited and contestable exceptions for self-determination27 or humanitarian intervention28—it obscures the degree to which borders and sovereign territory are man-made contingencies that can and sometimes should be voluntarily changed.29 Part of our goal here is to unsettle those assumptions and to suggest how private-law concepts like entitlement and transfer might be adapted to unwind the colonial structures they were once used to build. For generations, Western powers used private-law tools to exploit and profit from their colonies. Surely it requires some justification now to tell those colonies that the same tools are unavailable to them—that they, having enriched the metropoles, cannot pursue arguments of unjust enrichment; or that they, having been treated like property, cannot now choose to transfer or sell their territory. The conceptual and practical obstacles are considerable, and we address some of them below,30 but that is not reason enough to reject the effort, especially considering that the tools of public law have significant complications of their own.31

In fact, powerful and wealthy nations continue to use private-law tools to wring benefits from sovereign territories, for example by entering into long-term leases for military bases,32 or through large-scale industrial and public-works projects that have the effect of projecting sovereign authority abroad.33 This private-law toolkit—including concepts like contract (only possible once one has established entitlements) and damages—can be used to help the territories as well. This would not mean treating territories as “belonging to” the United States, subject to barter or trade as Congress sees fit.34 That notion should be rejected not because it involves property, but because it gives the entitlement to the wrong party—to the United States, rather than to the people of the territories.35 If colonial powers could, and in some ways still do, use sovereignty as a valuable asset, why can’t colonized people do the same now that the asset is theirs?

Getting clear about this entitlement helps illuminate the possibilities for what we have elsewhere described as a “market for sovereign control.”36 Sovereign control has been ceded, traded, gifted, leased, and otherwise transferred between nations for centuries. Sometimes those transfers have been coercive or exploitative; other times they have been voluntary and welfare-enhancing. What is generally missing, however, is a good legal mechanism for transfers of sovereignty beyond the context of former colonies becoming independent (which, it should be noted, many do not want).37 Sir Hersch Lauterpacht noted that “[t]he part of international law upon which private law has engrafted itself most deeply is that relating to acquisition of sovereignty over land, sea, and territorial waters.”38 But less attention has been paid to the use of private law in divesting territory.

One way to conceptualize the issue is as a question of allocating a valued resource—sovereign control over physical territory. In other contexts, the law assigns clear property rights, protects them, and lets parties bargain their way to mutual advantage, with appropriate constraints.39 Creating a market for sovereign control, then, would mean assigning property rights in sovereign control and permitting them to be traded. It would mean moving borders to fit people, rather than people to fit borders,40 subject to various limitations.41 But none of that is possible without clarity regarding the underlying entitlements. That is the focus of this Article.

Part I tells the story of Navassa, and how “the droppings of birds played an important role in the history of U.S. imperialism.”42 This historical account serves not only to give Navassa the attention it deserves in the law of the territories, but also to show how it—like the other unincorporated territories—ended up being treated as both property and sovereign territory, albeit without the benefits of either categorization.

Part II embeds this story in broader developments in legal thought and international law, beginning with Morris Cohen’s observation that seemingly obvious differences between property and sovereignty tend to blur the more deeply one thinks about them.43 In the case of the territories, that ambiguity was central both to the Insular Cases and to the interpretations of State Department lawyers. And yet, however blurry, the line remains significant, as contemporaneous developments in international law demonstrate. In particular, the move away from property-law concepts—long a staple of international law, especially with regard to the acquisition of territory44—and toward an emphasis on sovereignty has tended to cement the status quo, including existing colonial structures.

In Part III, using Navassa as an illustration, we argue that some aspects of the property paradigm should be recovered, and that they stand to help the U.S. territories and other colonial possessions. We explore three specific implications: negotiated economic settlements, litigation against colonial powers, and the possibility of auctions for sovereign control. The last of these, in particular, means adapting the property framework from uninhabited territories like Navassa to inhabited territories like Puerto Rico. By focusing on a small, uninhabited, and seemingly minor island, rather than mounting another attack on the Insular Cases, our goal is not to avoid the broader questions of democracy and the law of the territories, but to isolate and develop one particular theme: the use and potential promise of private-law concepts like property.