The film Casablanca (1942) has become a permanent icon of a certain kind of educated culture, at least among older generations. The cast will still be familiar, I hope: Humphrey Bogart, Ingrid Bergman, Peter Lorre, Sydney Greenstreet, Marcel Dalio, Conrad Veidt, Claude Rains. Its phrases have become part of our discourse, such as the endlessly misquoted "Play it again, Sam" or "Round up the usual suspects". If we leave aside the basic love affair, this is a film about the relations of the Spanish civil war and the wider politics of that strange but decisive period in 20th-century history, the era of Adolf Hitler. Rick, the hero, has fought for the republicans in the Spanish civil war. He emerges from it defeated and cynical in his Moroccan café, and the film ends with him returning to the struggle in the second world war. In short, Casablanca is about the mobilisation of anti-fascism in the 1930s. And those who mobilised against fascism before most others, and most passionately, were western intellectuals.
Today it is possible to see the civil war, Spain's contribution to the tragic history of that most brutal of centuries, the 20th, in its historical context. It was not, as the neoliberal François Furet argued it should have been, a war against both the ultra-right and the Comintern - a view shared, from a Trotskyist sectarian angle, by Ken Loach's powerful film Land and Freedom (1995). The only choice was between two sides, and liberal-democratic opinion overwhelmingly chose anti-fascism. Hence, asked in early 1939 who they wanted to win in a war between Russia and Germany, 83 per cent of Americans wanted a Russian victory. Spain was a war against Franco - that is to say, against the forces of fascism with which Franco was aligned - and 87 per cent of Americans favoured the republic. Alas, unlike in the second world war, the wrong side won. But it is largely due to the intellectuals, the artists and writers who mobilised so overwhelmingly in favour of the republic, that in this instance history has not been written by the victors.
The Spanish civil war was both at the centre and on the margin of the era of anti-fascism. It was central, since it was immediately seen as a European war between fascism and anti-fascism, almost as the first battle in the coming world war, some of the characteristic aspects of which - for example, air raids against civilian populations - it anticipated. But Spain took no part in the second world war. Franco's victory was to have no bearing on the collapse of France in 1940, and the experience of the republican armed forces was not relevant to the subsequent wartime resistance movements, even though in France these were largely composed of refugee Spanish republicans, and former international brigaders played a major role in those of other countries.
To situate the Spanish civil war within the general framework of the anti-fascist era, we have to bear in mind both the failure to resist fascism and the disproportionate success of anti-fascist mobilisation among Europe's intellectuals. I am referring not only to the success of fascist expansionism and the failure of the forces favouring peace to halt the apparently inevitable approach of another world war. I am also remembering the failure of its opponents to change public opinion. The only regions that saw a genuine political shift to the left after the Great Depression were Scandinavia and North America. Much of central and southern Europe was already under authoritarian governments or was to fall into their hands, but insofar as we can judge from the scattered electoral data, the drift in Hungary and Russia, not to mention among the German diaspora, was sharply to the right. On the other hand, the Popular Front's victory in France was a shift within the French left, not a shift of opinion to the left. The 1936 election gave the combined radicals, socialists and communists barely 1 per cent more votes than in 1932.
And yet, if I can reconstruct the feelings of that generation from personal memory, my generation of the left, whether we were intellectuals or not, did not see ourselves as a retreating minority. We did not think that fascism would inevitably continue to advance. We were sure that a new world would come. Given the logic of anti-fascist unity, only the failure of governments and progressive parties to unite against fascism accounted for our series of defeats.
This helps to explain the disproportionate shift towards the communists among those already on the left. But it also helps to explain our confidence as young intellectuals, for this social group was most easily, and disproportionately, mobilised against fascism. The reason is obvious. Fascism - even Italian fascism - was opposed in principle to the causes that defined and mobilised intellectuals as such, namely the values of the Enlightenment and the American and French revolutions. Except in Germany, with its powerful schools of theory critical of liberalism, there was no significant body of secular intellectuals who did not belong to this tradition. The Roman Catholic church had very few eminent intellectuals known and respected as such outside its own ranks. I am not denying that in some fields, notably literature, some of the most distinguished figures were clearly on the right - TS Eliot, Knut Hamsun, Ezra Pound, WB Yeats, Paul Claudel, Céline, Evelyn Waugh - but even in the armies of literature, the politically conscious right formed a modest regiment in the 1930s, except perhaps in France. Once again, this became evident in 1936. American writers, whether or not they accepted American neutrality, were overwhelmingly opposed to Franco, and Hollywood even more so. Of the British writers asked, five (Waugh, Eleanor Smith and Edmund Blunden among them) favoured the Nationalists, 16 were neutral (including Eliot, Charles Morgan, Pound, Alec Waugh, Sean O'Faolain, HG Wells and Vita Sackville-West) and 106 were for the republic, many of them passionately. As for Spain, there is no doubt where the poets of the Spanish language - those who are now remembered - stood: García Lorca, the brothers Machado, Alberti, Miguel Hernández, Neruda, Vallejo, Guillén.
This bias already operated against Italian fascism, even though it lacked at least two characteristics that were likely to make it unpopular among intellectuals: racism (until 1938) and hatred of modernism in the arts. Italian fascism did not lose the support of intellectuals, other than those already committed to the left in 1922, until the Spanish civil war. It seems that, with rare exceptions, Italian writers - very unlike German writers - did not emigrate during fascism. Therefore, 1936 forms a turning point in Italian cultural as well as political history. This may be a reason why the civil war has left few traces in Italian belles lettres, except in retrospect (Vittorini). Those who wrote about it at the time were the émigré activists: the Rossellis, Pacciardi, Nenni, Longo, Togliatti. On the other hand, against Germany intellectual anti-fascism operated from the moment Hitler took power, ritually burned the books of which Nazi ideology disapproved, and let loose a flood of ideological and racial emigrants.
The reactions of both intellectuals and the mobilised left to the Spanish civil war were spontaneous and massive. Here, at last, the advance of fascism was being resisted by arms. The appeal of armed resistance, being able to fight and not merely to talk, was almost certainly decisive. WH Auden, asked to go to Spain for the propaganda value of his name, wrote to a friend: "I shall probably be a bloody bad soldier. But how can I speak to/for them without becoming one?" I think it is safe to say that most politically conscious British students of my age group felt they ought to fight in Spain and had a bad conscience if they did not. The extraordinary wave of volunteers who went to fight for the republic is, I think, unique in the 20th century. The most reliable figure for the strength of the body of foreign volunteers fighting for the republic is around 35,000.
They were a very mixed bunch, socially, culturally and by personal background. And yet, as one of them, the English poet Laurie Lee, put it: "I believe we shared something else, unique to us at that time - the chance to make one grand and uncomplicated gesture of personal sacrifice and faith, which might never occur again ... few of us yet knew that we had come to a war of antique muskets and jamming machine-guns, to be led by brave but bewildered amateurs. But for the moment there were no half-truths and hesitations, we had found a new freedom, almost a new morality, and discovered a new Satan- fascism."
I am not claiming that the brigades were composed of intellectuals, even though volunteering for Spain, unlike joining the French Foreign Legion, implied a level of political consciousness, and certainly knowledge of the world, that most non-political workers did not have. For most of them, apart from those from neighbouring France, Spain was terra incognita, at best a shape in a school atlas. We know that the largest single body of international brigaders, the French (just under 9,000), overwhelmingly came from the working class - 92 per cent - and included no more than 1 per cent students and members of the liberal professions, virtually all of them communists. Given their technical qualifications, most of these were in fact employed behind the front lines. However, inside or outside the Brigades, the commitment, sometimes the practical commitment, of intellectuals is not in doubt. Writers supported Spain not only with money, speech and signatures, but they wrote about it, as Hemingway, Malraux, Bernanos and virtually all the notable contemporary young British poets - Auden, Spender, Day Lewis, MacNeice - did. Spain was the experience that was central to their lives between 1936 and 1939, even if they later kept it out of sight.
This was clearly so in my student days at Cambridge between 1936 and 1939. Not only was it the Spanish war that converted young men and women to the left, but we were inspired by the specific example of those who went to fight in Spain. Anyone entering the rooms of Cambridge socialist and communist students in those days was almost certain to find in them the photograph of John Cornford, intellectual, poet and leader of the student Communist Party, who had fallen in battle in Spain on his 21st birthday, in December 1936. Like the familiar photo of Che Guevara, it was a powerful, iconic image - but it was closer to us, and, standing on our mantelpieces, it was a daily reminder of what we were fighting for. As it happens, not many Cambridge or other students went to fight in Spain after the Communist Party of Great Britain decided to discourage students from volunteering for the international brigades unless they had special military qualifications. Many of those who fought had joined the republican forces before the party established this policy. Nevertheless, the British international brigaders contained a significant number of talented intellectuals, of whom several fell. So far as I am aware, none of those who survived has expressed regret for his decision to fight.
Among the losers, polemics about the civil war, often bad-tempered, have never ceased since 1939. This was not so while the war was still continuing, although such incidents as the banning of the dissident Marxist Poum party and the murder of its leader Andrés Nin caused some international protest. Plainly a number of foreign volunteers arriving in Spain, intellectuals or not, were shocked by what they saw there, by suffering and atrocity, by the ruthlessness of warfare, brutality and bureaucracy on their own side or, insofar as they were aware of them, the intrigues and political feuds within the republic, by the behaviour of the Russians and much else. Again, the arguments between the communists and their adversaries never ceased. And yet, during the war, the doubters remained silent once they left Spain. They did not want to give aid to the enemies of the great cause. After their return, Simone Weil, though patently disappointed, said not a word. Auden wrote nothing, though he modified his great 1937 poem "Spain" in 1939 and refused to allow it to be reprinted in 1950. Faced with Stalin's terror, Louis Fischer, a journalist closely associated with Moscow, denounced his past loyalties - but he took trouble to do so only when this gesture could no longer harm the Spanish republic. The exception proves the rule: George Orwell's Homage to Catalonia. It was refused by Orwell's regular publisher, Victor Gollancz, "believing, as did many people on the left, that everything should be sacrificed in order to preserve a common front against the rise of fascism". The same reason was given by Kingsley Martin, editor of the influential weekly New Statesman & Nation, for accepting a critical book review. They represented the views overwhelmingly prevalent on the left. Orwell himself admitted after his return from Spain that "a number of people have said to me with varying degrees of frankness that one must not tell the truth about what is happening in Spain and the part played by the Communist Party because to do so would prejudice public opinion against the Spanish government and so aid Franco". Indeed, as Orwell himself recognised in a letter to a friendly reviewer, "what you say about not letting the fascists in owing to dissensions between ourselves is very true". More than this: the public showed no interest in the book. It was published in 1938, in a run of 1,500 copies, which sold so poorly that the stock was not yet exhausted 13 years later when it was first reprinted. Only in the cold-war era did Orwell cease to be an awkward, marginal figure.
Of course, the posthumous polemics about the Spanish war are legitimate, and indeed essential - but only if we separate out debate on real issues from the parti pris of political sectarianism, cold-war propaganda and pure ignorance of a forgotten past. The major question at issue in the Spanish civil war was, and remains, how social revolution and war were related on the republican side. The Spanish civil war was, or began as, both. It was a war born of the resistance of a legitimate government, with the help of a popular mobilisation, against a partially successful military coup; and, in important parts of Spain, the spontaneous transformation of the mobilisation into a social revolution. A serious war conducted by a government requires structure, discipline and a degree of centralisation. What characterises social revolutions like that of 1936 is local initiative, spontaneity, independence of, or even resistance to, higher authority - this was especially so given the unique strength of anarchism in Spain.
In short, what was and remains at issue in these debates is what divided Marx and Bakunin. Polemics about the dissident Marxist Poum are irrelevant here and, given that party's small size and marginal role in the civil war, barely significant. They belong to the history of ideological struggles within the international communist movement or, if one prefers, of Stalin's ruthless war against Trotskyism with which his agents (wrongly) identified it. The conflict between libertarian enthusiasm and disciplined organisation, between social revolution and winning a war, remains real in the Spanish civil war, even if we suppose that the USSR and the Communist Party wanted the war to end in revolution and that the parts of the economy socialised by the anarchists (ie handed over to local workers' control) worked well enough. Wars, however flexible the chains of command, cannot be fought, or war economies run, in a libertarian fashion. The Spanish civil war could not have been waged, let alone won, along Orwellian lines.
However, in a more general sense, the conflict between revolution as the aspiration to freedom and winning war is not purely Spanish. It has emerged fully after the victory of revolutions in wars of liberation: in Algeria, probably in Vietnam, certainly in Yugoslavia. Since the left lost in the Spanish civil war, in this case the debate is posthumous and increasingly remote from the realities of the time, like Ken Loach's film, inspiring and moving as it is. Moral revulsion against Stalinism and the behaviour of its agents in Spain is justified. It is right to criticise the communist conviction that the only revolution that counted was one that brought the party a monopoly of power. And yet these considerations are not central to the problem of the civil war. Marx would have had to confront Bakunin even if all on the republican side had been angels. But it must be said that, among those who fought for the republic as soldiers, most found Marx more relevant than Bakunin - even though some survivors may recall the spontaneous but inefficient euphoria of the anarchist phase of liberation with tenderness as well as exasperation.
After its brief moment at the centre of world history, Spain returned to its position on its margin. Outside Spain, the civil war lived on, as it still does among the rapidly diminishing number of its non-Spanish contemporaries. It became and has remained something remembered by those who were young at the time like the heart-rending and indestructible memory of a first great and lost love. This is not the case in Spain itself, where all experienced the tragic, murderous and complex impact of civil war, obscured as it was by the mythology and manipulation of the regime of the victors. Nonetheless, in creating the world's memory of the Spanish civil war, the pen, the brush and the camera wielded on behalf of the defeated have proved mightier than the sword and the power of those who won.
· Eric Hobsbawm's Revolutionaries will be reissued in April, and Globalisation, Democracy and Terrorism will be published in July, both by Little, Brown. Price £9.99 and £20 respectively.