Nele Kortendiek’s book Global Governance on the Ground (2024) is a though provoking and timely contribution to the study of migration, asylum, and international organizations (IOs) and migration governance more generally. Its central argument is that governance of migration and asylum does not only happen via formal rules, policies, and state diplomacy but also through everyday practices “on the ground”—that is, via field staff from IOs, Non-Governmental Organizations (NGOs), European Union (EU) agencies, and operational actors who improvise, adapt, and fill regulatory and normative gaps. Kortendiek coins the term governance on the ground to capture this mode of global governance characterised by low institutional threshold, informal authority, and situated learning. The empirical focus of the book is the European external border during the 2015–2016 migration and refugee crisis, particularly in Greece. Her evidence draws on rigorous ethnographic fieldwork, numerous interviews with key informants in IOs like United Nations High Commissioner for Refugees (UNHCR), International Organization for Migration (IOM), Frontex, European asylum support, and NGOs, plus document analysis which brings extensive knowledge to the topic.

The book has several strengths. First and perhaps foremost is the innovative theoretical framing of the analysis. By shifting attention from mandates, rules, and formal authority to practice, situated knowledge, improvisation, and field-level action, she contributes to the flourishing “practice turn” scholarship. This is especially valuable in migration studies, where many of the crises and governance “failures” or “gaps” occur not because rules are absent but because the implementation in concrete border spaces is messy, contested, and informal. Her simple definition of governance—taken to mean the organization of collective action, with enabling or constraining effects—broadens the analytical lens beyond classic authority-based models.

Second, the triangulated and empirically rich data bring insight and nuance to this complicated topic. The empirical work is comprehensive: ethnographic fieldwork in Greece, interviews with staff both in the field and at headquarters, and document analysis. This mix allows her to trace how practices emerge in the field, how field staff improvise responses during high pressure situations, and how those practices are eventually stabilized and diffused (or not) through headquarters, standard operating procedures, or best practices. The book shows how field actors do not merely carry out mandates from headquarters but actively contribute to defining what governance is in practice.

Third, the case of mixed migration is well chosen: it sits at the intersection of state sovereignty, humanitarianism, asylum law, migration control, NGO practice, and international politics. The author demonstrates how during the so-called European migration crisis, the formal governance landscape was fragmented, overlapping, and often contradictory, leaving space for field actors to act. Thus, the book furthers our understanding on the politics of mixed migration, as well as IO behavior in spaces of crisis and contestation. While this approach works well for the case of irregular migration, it is a theoretical framework that can easily be translated to other fields where emergencies and rapid responses to them are necessary.

Finally, by making these informal practices visible, the book opens space for normative scrutiny. For example, who decides in these field practices? Who benefits? Who is accountable? When field actors improvise, whose values guide them? What are the justice implications? Kortendiek raises these questions, in so doing spotlighting areas for engagement for migration scholars concerned with rights, justice, and power.

While the book makes substantial contributions, there are also some limitations and areas for further refinement, though some have already been mentioned in the book’s conclusion. For example, while the empirical case chosen (European external border, Greece, 2015–16 crisis) makes sense, it is not clear how generalizable this model of governance on the ground is for other geographies, migration regimes, or crises. Migration scholars often caution that European border contexts are highly exceptional in terms of resources, political attention, legal regimes, media visibility, and involvement of NGOs/IOs. How do field practices differ in regions with weaker IO presence, non‑European borders, or in contexts where states strictly limit IO access?

While Kortendiek raises normative implications, the book might be critiqued for insufficient attention to mechanisms of accountability, oversight, and the potential downsides of informal, improvisational governance. When field staff improvise, there is a heightened risk of arbitrariness, inconsistent treatment, bias, and the violation of rights. How are such risks mitigated? What about legal responsibilities under asylum or international human rights law? The book does touch on these issues, but given migration scholars’ concern with protection, rights, due process, more sustained attention would have strengthened the argument’s normative dimension. It would also have been relevant to consider how informal governance maps onto state sovereignty discussions, given the continued primacy of the state.

The book shows how some field practices become more formalized or diffused across sites. However, it remains unclear how durable those practices are over time: do they survive political changes, funding cuts, regulatory shifts, or crises of legitimacy? Are they institutionalized in such a way that preserves their positive aspects (flexibility, responsiveness) while containing risks (lack of transparency, inequality)? In migration contexts, what is “on the ground” often faces pressures from national governments, media, political backlash, or changing EU policies. Exploring their resilience would have added an interesting facet to this discussion.

Although the book addresses crisis and contestation, that analysis could have been enriched by a more detailed tracing of how state policies, political pressures, funding, donor preferences, and legal constraints shape what field practices are possible or not. Some practices may be constrained not just by absence of mandate, but by political or legal risk. Also, while IOs and NGOs have practical leeway, field staff may also be constrained in ways that the “practice” perspective underplays: for example, by their headquarters, by the expectations of states, by normative frameworks that still limit what they can do, or by resource constraints. More attention to those constraints would sharpen how much room field actors really have.

Overall, the book is a clear contribution to the field, bringing together international relations and migration studies in a unique way. Its focus on field practice fills a gap: migration governance is often studied either from macrostructures (states, treaties, policies) or from the bottom (migrant experiences), while the meso‑level of operational actors is less theorized. Kortendiek’s book helps us understand how IOs actually operate, how norms and practices emerge in improvisational, uncertain conditions, and how these practices have real consequences for people’s lives.

In migration studies, this book deepens our understanding of mixed migration governance, exposing how ambiguous categories, legal gaps, and overlapping responsibilities create space for informal modes of governance. It also underscores the importance of field‑level practices for outcomes: how migrants are registered, processed, guided, or excluded is shaped significantly by what happens on the ground, often in ways not visible in policy documents.