Soon after its formal establishment in 1935, the International Institute of Social History (IISH) launched its journal, then known as the International Review for Social History. The early years of both the IISH and its periodical draw attention to several manifestations of transnational activism. In practice, the institute's remit “to promote the knowledge and the scientific study of national and international social history in the full sense of the word” meant that it collected material on social movements that operated on an international scale and that involved various forms of cross-border cooperation.Footnote ¹ Moreover, from the outset, the IISH's journal was concerned with transnationalism avant la lettre. For example, the inaugural issue of the International Review included an article on the writings of Russian anarchist Mikhail Bakunin during his Dresden sojourn in 1849, while another piece discussed the creation of a Prague-based archive containing documents from Russian émigrés.Footnote ² The Russian author of the latter contribution was not the only exile who featured in the journal's first volume: others included Kurt Baschwitz, Helmut Hirsch and Hans Stein, all of whom had fled Nazi Germany in 1933.Footnote ³

While these examples do not feature in my book on Activism across Borders since 1870, they could have easily found a place in it, for several reasons. After all, at one level, they draw attention to exile as a consequence, locus and progenitor of transnational activism.Footnote ⁴ Moreover, the IISH's history relates to ideas and movements in which internationalism featured prominently – even beyond the content of its collections. For instance, IISH founder Nicolaas Wilhelmus Posthumus was active in socialist circles, while Hans Stein, who headed the institute's German department, had been a member of the German Communist Party and spent some time working at the Marx-Engels Institute in Moscow.Footnote ⁵

There is yet another element that ties in with the subject of my book. The origins and efforts of the IISH remind us that many activists were keen to place their campaigns within a historical context: they frequently referenced past events and exhibited a commitment to constructing or maintaining an activist memory related to their cause.Footnote ⁶ From this perspective, both the IISH's creation and the first incarnation of its International Review constituted forms of activism in their own right, as they made an implicit argument about the value of preserving such histories. A related venture was the foundation of the International Archive for the Women's Movement, with the activist Rosa Manus and two scholars, Johanna Naber and Willemijn Posthumus-van der Goot, jointly establishing this body in Amsterdam in 1935.Footnote ⁷ Activism, archiving, academia and historical narrative could intersect in multiple ways.

In the light of these observations – and my productive experiences of using IISH collections over the years – I am grateful that the International Review of Social History has provided space for a detailed discussion of my book. The contributions to this review dossier include stimulating pieces from historians who specialize in the histories of internationalism (Jessica Reinisch), anarchism (Constance Bantman), labour and women's activism (Nicole Robertson), human rights (Mark Hurst) as well as humanitarianism and student life (Georgina Brewis). The particular emphases chosen by each author illustrate how the book's broader framework can be applied to different varieties of activism. For example, Hurst uses the four analytical lenses from my introduction – “connectedness”, “ambivalence”, “transience”, and “marginality” – to shed light on human rights activism. Robertson also picks up on this aspect of the book, for example by noting how transnational connections could overcome marginalization in the national sphere.Footnote ⁸ Moreover, when taken together, the five pieces make the case for treating transnational activism as a multifaceted phenomenon with different, yet interrelated, histories.

It is worth noting that, apart from some earlier isolated examples, the term “transnational activism” only entered the scholarly lexicon around the year 2000. When it did gain greater currency in the early 2000s, it was with a focus on contemporaneous social and political mobilizations – even when such work acknowledged various historical precedents.Footnote ⁹ Soon thereafter, however, explicit references to “transnational activism” also began to appear in studies of a more historical nature.Footnote ¹⁰ That said, as late as 2018, Stefan Berger and Sean Scalmer argued that “the history of the ‘transnational activism’ remains to be written” and took a step in this direction by editing a volume on this subject.Footnote ¹¹ My own book does not purport to be novel in the historical application of the concept itself – yet it does make a case for understanding “transnational activism” as a phenomenon that we can trace both across time and across different causes. I therefore appreciate that the contributors to this dossier have acknowledged the value of such an undertaking. Brewis has stressed the insights offered by a “longue durée” approach to the study of activism. Moreover, Hurst notes that the book's integrated approach illuminates aspects that a more isolated treatment of individual movements or campaigns cannot do. In this respect, he identifies a central concern of mine: the need to avoid compartmentalizing our treatment of activism(s). Many activists saw their pursuit of one cause as being entwined with various others, even when they prioritized particular concerns and commitments.

Activism across Borders since 1870 stresses the wide-ranging, interrelated and overlapping commitments of activists, presenting “connectedness” as one major perspective through which we can examine the phenomenon under consideration. Meanwhile, Bantman's contribution indicates that we can also understand connectedness in another way: by linking together different forms of activism within a transnational framework, we can reassess our overall perspective regarding the peripherality of particular movements or groups. Bantman's own work has demonstrated the extent of transnational networking among anarchists.Footnote ¹² For this reason, anarchism appears less peripheral when the emphasis is on transnational, rather than national-level, activism: as I note in my book, the transnational spaces that anarchists moved in, the international issues they campaigned on, as well as the theoretical debates they engaged in, frequently intersected with those of other groups. Recent work on the concept of “direct action” – which anarchists developed but which was subsequently taken up in different social and political contexts – provides further examples of such interactions.Footnote ¹³

While it is important to identify connections and exchanges between various activists, my book does not downplay impulses that moved into the opposite direction. Decoupling, rupture and outright antagonism were central to the experience of many activists. The use of the word “Conflicts” in the book title alludes to this aspect. In this review dossier, Robertson directly picks up on this strand, as she highlights disputes on equality protection for women workers as well as divisions regarding the representation of non-manual workers within the labour movement and international organizations.

Moreover, activists’ insistence on the connectedness of different causes does not necessarily create alliances: it can also rupture them. Recent controversies involving Greta Thunberg and other climate activists illustrate this point. As Brewis points out in her contribution to this review dossier, Thunberg's dedication to action against climate change has made her a transnational icon.Footnote ¹⁴ In 2023, however, Thunberg vociferously associated herself with another cause, namely Palestine solidarity. In October that year, she responded to the conflict in Gaza by urging a “climate strike for Palestine”.Footnote ¹⁵ Other activists adopted a similar perspective, with the Dutch branch of Extinction Rebellion staging a pro-Palestinian protest in front of the International Criminal Court.Footnote ¹⁶ Moreover, in November 2023, Amsterdam was the site of a climate change protest in which Thunberg argued that there could be “no climate justice on occupied land”.Footnote ¹⁷ Such pronouncements generated controversy, both at the demonstration in the Dutch capital and more generally. For example, key figures from the German “Fridays for Future” movement expressed their disappointment with Thunberg, not just because they disagreed with her position, but also with the way in which it was being articulated.Footnote ¹⁸ This example highlights a broader tension: what some activists might see as a holistic approach to activism (in this case linking environmental activism and the politics of solidarity) might appear divisive to others.

Ruptures within particular movements – and hence among those who generally considered themselves allies – are only one example of the way in which transnational activism can be understood not just as a phenomenon, but as a dynamic process. A consideration of transnational counter-reactions and opposing forces reinforces this aspect. As Bantman's essay notes, international anarchism spawned international cooperation by governments that sought to limit the movement and leeway of suspected radicals – in some ways rendering borders less permeable.Footnote ¹⁹ A more recent example is the way in which some multinational corporations responded to the rise of environmentalist concerns. By funding ventures that cast doubts on the nature of human-induced climate change, they have created a “denial machine” in which business interests converge with the agenda of activists who object to state intervention on ideological grounds.Footnote ²⁰

I mention this interplay as it also relates to another key aspect of my book. In his essay, Hurst has rightly noted that Activism across Borders since 1870 does not limit itself to seemingly “progressive” causes. Indeed, my introduction stresses that activism and transnational cooperation covered a broad political and ideological spectrum.Footnote ²¹ To this end, my book's discussion extends to groups and movements whose positions were far removed from, or directly opposed to, the left. For instance, while anti-racist campaigns and anti-fascist mobilizations feature prominently, the book notes that groups on the far right maintained various transnational ties, too, either directly or implicitly referencing movements they opposed.Footnote ²² Given the pronounced nationalism of such movements, many of their transnational links proved ephemeral, and, on the whole, such groups rarely managed to forge or sustain notions of a shared activist history. In her introduction to this review dossier, Reinisch describes this acknowledgement of political variegation as an important feature of the book's approach to transnational activism, although she concedes that it may appear controversial. We do indeed need to understand transnational activism as a vessel for widely different views. By covering activists who stood at opposite ideological poles, as well as those who occupied the space in between, we can discern how even mutually hostile kinds of activism could feed on one another, be it by emulating existing strategies or by consciously casting their own alliance as a counterpart to an existing transnational entity.Footnote ²³

An understanding of such diversity can also help us avoid overly optimistic narratives. This is not just the case when thinking about transnational activism in general terms, but also when discussing particular varieties. For instance, an extensive body of work now problematizes humanitarianism, highlighting features that were far from benign, especially in view of its connections to the politics of empire.Footnote ²⁴ In my book, this aspect is a central concern in Chapter 1, although it is also reflected in the study's general emphasis on “ambivalence”.Footnote ²⁵ More generally, the discussion in Activism across Borders since 1870 repeatedly highlights the actions of individuals or groups that, while portraying themselves as “inclusive”, had features that reinforced existing inequalities.Footnote ²⁶

These observations tie in with a wider issue raised by contributions to this review dossier: the question of whom we may (or may not) consider to be an “activist”. Robertson mentions the case of white-collar workers who sought to overcome perceptions that seemed to complicate the pursuit of their social demands. Meanwhile, Brewis's piece draws attention to the question of youth. As she rightly points out, young people feature prominently in representations and perceptions of activism. The role of “1968” both as a year of widespread student activism and as a byword for radical protest is arguably the most obvious manifestation of this phenomenon. Yet it is also clear that youth featured prominently in a variety of international movements, both as protagonists and targets of activist ventures.Footnote ²⁷

At the same time, a focus on youth should not overshadow the extent to which many forms of transnational activism were characterized by inter-generational cooperation. In considering the promotion of alternatives to neoliberal globalization during the early 2000s, Donatella della Porta characterized the European Social Forum as “heterogenous not just socially, but also generationally, as well as seeking to bring differing and remote national cultures together”.Footnote ²⁸ Yet similar descriptions apply to many other activist ventures. While such alliances might be temporary – hence the analytical lens of “transience” in my book – they are nonetheless important. Given such heterogeneity, it is possible to undertake further research on how a shared sense of being an “activist” was being developed in different historical contexts. Some work has shown that a histories of emotions approach – which is fairly well-established in the consideration of local or national groups of activists – is also fruitful when considering transnational settings.Footnote ²⁹

This observation points to the wider question of activist identities. Sidney Tarrow initially spoke of “rooted cosmopolitans” when discussing activists in the early 2000s, but since then, his concept has been taken up more widely in the scholarly literature and is now being applied to different periods and protagonists.Footnote ³⁰ In her contribution to this review dossier, Bantman asks how we might take this emphasis on “rootedness” further. At one level, my book emphasizes rootedness in national contexts and thus acknowledges research that stresses the entwined nature of nationalism and internationalism.Footnote ³¹ Clearly, writing a history of transnational activism does not mean to write a history without the nation, because – whether they acknowledged it or not – national frameworks, ideas and convictions continued to matter to many activists.

That said, it is worth adding another form of “rootedness” to the discussion: namely the intermediate levels between the local and national on the one side and the global or universal on the other. While many activists spoke in terms of seemingly global concepts – “class”, “sex”, “gender” and “race”, to mention the most prominent examples – in practice, such categories had different meanings and impacted on activism in different ways. It is therefore possible to identify “region” as a central category and level of identification for activists. While consciously seeking to transcend the nation, they were “rooted” in specific regional contexts.Footnote ³²

At one level, this aspect matters even when looking at developments within Europe. After all, Europe was not a stable or homogenous entity. Accordingly, different parts of my book bring specific European regions into focus, both as sites of activism and as objects of activist concern. This observation relates to another question raised in Bantman's essay – that is, how to write about activism on a potentially global scale. The book's sub-title of speaks of “Causes, Campaigns and Conflicts in and beyond Europe”. Europe is a point of departure for my study, yet it is clear that we cannot write the history of transnational activism in Europe in isolation from other world regions. As such, the book takes global frameworks, connections and inequalities seriously. At the same time, it does not purport to be a global history, but rather constitutes an attempt to approach the history of modern and contemporary Europe in different ways.Footnote ³³ Recent research cautions us again speaking of “global history” in ways that privilege the European context. For example, researchers on the history of humanitarianism have stressed efforts to write the history of this phenomenon beyond the West, or even without the West.Footnote ³⁴ Moreover, we are increasingly alert to the fact that the categorizations associated with activism were heavily contested, with campaigners from the Global South challenging the assumptions, priorities and methods of their presumed (or self-declared) allies.

Su Lin Lewis has recently made a compelling case for using histories of transnational activism to “decolonize” histories of internationalism.Footnote ³⁵ As she acknowledges, this work is already under way. One example is the stimulating research that investigates different varieties of South–South activism.Footnote ³⁶ Well beyond Activism across Borders since 1870, then, there is hence a growing and diverse literature on the subject of transnational activism. Such research indicates that it is possible to acknowledge its nature as a phenomenon in which several causes – for instance socialism, feminism, pacifism and anticolonialism – became entwined, while also drawing attention to centrifugal tendencies and problematic undercurrents. This burgeoning area of research is likely to generate many further histories of transnational activism. Undoubtedly, such work will differ substantially from mine, fruitfully highlighting different causes, protagonists, settings, strategies and tensions.