Depending on who is speaking, the tipping point beyond which a two-state solution to the Israeli–Palestinian conflict becomes impossible is approaching, imminent, or passed. Raja Khalidi, in the opening to his chapter in One Land Two States, writes “[it] does not take an expert to recognize that a partition of territory and sovereignty on the basis of geo-demographic realities today is most likely not a viable solution.” A binational or civic one-state democracy seems remote and undesirable, or else a formula for entrenched apartheid.

As a result, those who believe the conflict must be resolved and not just managed are increasingly exploring ideas that acknowledge both the need for separation, but accept that the land is small and the populations increasingly inextricable.

One Land Two States is one of the only book-length works to explore a specific separate-but-together model in theoretical and practical depth. It adds to a slow but steady growth of academic literature considering confederal proposals for the Israeli–Palestinian conflict. One Land Two States grew out of the “Parallel States Project,” a group of prescient academics who began their discussions in 2008; the chapters in this edited collection were written by participants in that project. The academic interest complements a similar flurry of activity on the ground. Local civil society efforts have yielded confederal projects with similar names, such as Two States, One Homeland and Two States, One Space.

Benjamin Netanyahu's recent re-election in March gives the issue new urgency. The fallacy of a status quo has been shattered by a trio of wars in Gaza and Netanyahu's election-eve rejection of the two-state concept, as well as more aggressive Palestinian activity in the international arena. Israel is deepening its grip on “Area C”—60 percent of the West Bank—and coalition partner Naftali Bennett, among others, has called openly for annexation.

Strict two-staters have argued that confederal approaches are unrealistic slogans. But radical political changes can indeed start as broad ideas, fleshed out over time by new proponents. This book advances that process, through theoretical discussions of sovereignty, elaborate proposals for security and economy, law, and even the role of religion. It is comprehensive, detailed, and confronts problems at every step; accusations of sloganism or naiveté do not apply.

Several chapters are devoted to disaggregating the elements of sovereignty and putting them together again differently. Jens Bartelson summarizes the main criticisms of traditional sovereignty, then ups the ante: if we accept that classic territorial inviolability has been breached over history, if political ownership is increasingly delinked from land, then what? That's when the authors take the leap, in proposing sovereignty based on identity, rights, individuals, and law.

The result is a tantalizing proposal for “parallel states” (which could more accurately be called layered states, since “parallel” implies side-by-side but never touching). The two states would be defined by citizenship rather than geography or borders. “Heartland” areas dominated by one of the national groups would be small and limited—all the rest is open season: “Two parallel state structures, both covering the whole territory, with one answering to Palestinians and one to Israelis regardless of where they live” (p. 2).

What can this putatively simple formulation mean? Can two different governments on the same land be a fair and functional way of managing life for two integrated but hostile populations?

The authors do not underestimate the theoretical challenge, calling it “conceptually demanding.” Mossberg, a former diplomat, proposes that sovereign powers can be divided between shared and separate authorities, through vertical sovereignty (citizenship for individuals at the local, state, and confederate level) as well as horizontal sovereignty, side-by-side governments and leaders. The European Union is a model for comparison, but the description also recalls Bosnia, a complex, not always stable arrangement—which has nonetheless preserved nonviolence for twenty years to date.

There is an aura of relief associated with the notion of breaking open the borders. It psychologically relaxes the current chokehold of movement restrictions, walls, segregated roads and tortured de facto borders that would define a two-state solution—and possibly render it a failure.

Israelis argue that those temporary-cum-permanent arrangements are security requirements. Therefore it is no surprise that the first two policy-oriented chapters are devoted to security, always the top test of relevance for potential solutions to the Israeli–Palestinian conflict.

The chapters are wisely written separately by Israelis and Palestinians, acknowledging the reality of different perceived security needs rather than false togetherness. The Israelis propose elaborate separate, joint, and international security bodies, constructed in phases, bolstered by layers of agreements. The Palestinian chapter reviews the multilayered security needs for a population under occupation for decades, but also scattered and stateless. Both pairs of authors propose an international security presence and the need for a regional approach—another increasingly prominent theme being heard lately.

The two economic chapters—also authored separately by a Palestinian and an Israeli—propose how the model might generate a joint economy. The authors establish equality between the two sides as the guiding principle while grappling with the competing needs of ending the occupation and building a model for the future (“Such a vision must not be an academic exercise for a rosy postliberation future, but instead must contribute to a strategy for Palestinian liberation,” [p. 137]). Throughout the book and here too, the correct dosage of separation versus integration is a lingering question and they do not claim to have hard answers.

Numerous participants contributed to a conversational chapter about parallel legal systems. In defense of the idea that two people living on the same block would live under different laws, it is somewhat unfortunate that they cite precedents of medieval monarchies, the Ottoman system or religious authorities—all premodern and not naturally amenable to democratic societies. The European Union is a healthier inspiration, although that system is predicated on the harmonization of laws, which receives only passing attention. Yet the authors never conclude in triumph and use only cautious optimism about the possibility of a functioning legal system based on parallel state principles.

The proposals are rich and the problems are many but the authors rarely sterilize the circumstances to advance the cause. And the two-state solution under the current circumstances may raise just as many, if different, obstacles. Still, a few specific concerns emerge that can be monitored as such ideas develop; these may be relevant for the parallel states model or the other ones above.

First, the various proposals for separate as well as joint structures mean cumbersome administration of security, economy, and law. For each there would be at least three bodies; the security chapters go further in adding an international presence. These could create bureaucracy as suffocating and opaque as the borders they hope to erase. Next, most of the ideas rest heavily on phased transitions, over decades. Given deep and fresh hostilities, this makes sense. Yet the Oslo experience also shows the danger of phased progress and conditionality, which was unable to withstand events on the ground.

A chapter on religious dimensions of the conflict is valuable but could perhaps have been better spent exploring how identity would be demarcated in the parallel states: symbolism in public spaces is addressed in just one paragraph. But the identity and symbolism of society is far more than just flags: it is the national calendar, the ceremonies and memories of shared spaces, the rhythm of life.

The unpopular fact is that there is declining agreement between the two parties on the end goal of a two state solution. Maybe that's why the process to get there is failing. Perhaps if new energy can be generated around a different end point, the process stands a better chance of working. But it will take a long time—and probably bloodshed.