When realists think about climate change at all, it’s often as the precursor for yet another demand for increased military spending. The spectre of millions of climate change refugees voting with their feet and trampling national borders ought to focus the attention of even the most traditionally minded of defence planners and strategic analysts. The wonder is that climate change is not at the forefront of security debates given that the impact it has already had is incontrovertible.

Anatol Lieven, whose latest book, Climate change and the nation state: The case for nationalism in a warming world ^[1], was published in March, has the distinction of being a self-confessed realist who takes climate change seriously. Hopefully, the fact that he is suitably hard-headed about the reality of climate change and its rapidly escalating consequences will mean that this book will actually be read by policymakers and the analysts who influence their thinking. Whether it will change their minds is another question, of course. As Lieven points out, the influence of what he calls ‘residual elites’ persists because relatively successful orders are difficult to change.

Unsurprisingly, perhaps, Lieven considers the nation-state to have been the key actor in shaping the modern world—and until recently that’s generally been a good thing. Where he departs from other realist analysts, however, is in his assessment of the nature of security threats in a state-based system. One of the most important—and accurate, in my view—claims that he makes is that ‘[b]arring a full-scale nuclear exchange between the great powers, no security threat in the world today comes anywhere near to matching the threat posed by climate change to existing states’.

While environmentalists may welcome this overdue recognition of the relative importance of the real rather than hypothetical threats to state security, they are unlikely to agree with some of his ideas about how to save the planet—or those bits of it that are still more or less in working order, at least.

His policy recommendations are directed primarily towards policymakers in the Western liberal democracies. Unless they can rapidly address the all too visible consequences of global warming, he claims, they will ‘ultimately face a choice between authoritarian rule and complete political and social collapse’. The only hope in such circumstances is to mobilise the populations of individual countries around forms of progressive nationalism.

In this regard, he is enthusiastic about the potential of a ‘Green New Deal’, albeit one that is dedicated solely to job creation and economic renewal along sustainable lines, and not side-tracked by what he sees as a host of other ‘extraneous causes’. Indeed, the analysis of the domestic political scene in the United States is especially acute: unless Democrats adopt a more inclusive, less condescending political discourse, they are unlikely to win back the members of the white working class who abandoned them to support Trump.

Despite all of the crises and problems that have plagued capitalism over the past few years, it must be reformed rather than abandoned, he argues. The ‘dogmatic free-market capitalist ideology’ promoted under the rubric of the Washington consensus has clearly failed and brought divisive inequality and insecurity in its wake. The only alternative, Lieven argues, is ‘massive state involvement, in terms of direct subsidies, incentives, and compulsions’, to develop a more inclusive and sustainable social and political order.

The most unpalatable part of the book for those of a more cosmopolitan cast of mind is his argument that migration must be tightly controlled if individual national communities are to unite around a common cause. It is no longer outlandish to suggest that mass migration is likely to be the defining issue of this century—its potential effects are already clear in the rise of populist leaders in Europe and elsewhere.

Lieven argues that the support for open borders advocated by Green parties and the left will only ‘feed white chauvinism, tear their societies apart, and make effective action to limit climate change impossible’. I fear he may be right. At the very least, it’s an important reminder that we are already in a world of second-best options and potentially unstoppable tipping points, and not just of the environmental variety.

The overarching argument that only nation-states have the capacity to act in ways that can make a decisive difference is depressingly persuasive. Even more alarmingly, some of the most effective responses have come from authoritarian governments, like China, which has rapidly become the world’s leading investor in renewable energy. Unless democratic governments—like ours—actually recognise the immediacy of the dangers that confront even the seemingly most stable and secure of countries, comforting rhetoric about ‘getting through this’ may no longer cut much ice.

The great redeeming feature of the realist tradition is that its exponents do try to let the facts dictate the argument, rather than vice versa. This doesn’t mean that their conclusions or their arguments are always right—far from it. The Morrison government’s decision to spend money on military hardware rather than climate change mitigation is the latest example of this possibility. But it does mean that realists may recognise the implications of problems that we might otherwise prefer not to think about.

Climate change is the quintessential, implacable and, by this stage, possibly unstoppable threat we all face. The consequences of failing to recognise this unambiguous reality are spelled out in this sensible and sobering book. Even if you don’t like its answers and conclusions, you ought to read it if you’re remotely interested in the future of a world that is increasingly plagued by insecurities and problems our leaders seem incapable of addressing.