The Jewish contribution to the politics of the left has always been complex, sometimes contradictory and often of fundamental importance. Labour's current crisis is one more phase in a close and chequered relationship.
Left-leaning Jews have always been a minority within the Jewish community. But left-wing Jews were often at the heart of "left" politics, whether "left" is defined as anarchist, communist or social democratic. Anarchist activism and communist success are history, and the social democratic tendency is in crisis. However, the rise and fall of revolutionary Jewish politics may have lessons for the future.
A new volume of essays, A Vanished Ideology, edited by Matthew Hoffman and Henry Srebrnik, throws fresh light on the history of the Jewish Communist movement in the Anglophone world; while Philip Mendes's recent volume, Jews and the Left (2014), illuminates Jewish involvement across the range of left politics.
Some commentators argue that the left has always been fundamentally hostile to the Jewish community. From Karl Marx onwards, Jews faced occasional left hostility and, in the late 1940s, outright persecution at the hands of the Communists. However, there was a long-term political alliance with roots going back to the beginnings of modern radicalism in Europe.
The emancipatory ideals of revolutionary and enlightenment Europe opened the way for greater Jewish engagement in politics, enhanced by the Jewish enlightenment, the Haskalah. As a result, Jews were heavily involved in the revolutions of 1848, fighting against the old regime, but also for Jewish equality and the rights of minorities. Jewish intellectuals including Moses Hess, Marx, and Ferdinand Lassalle worked to develop the new revolutionary critique of state and society. Their leading role, and the influence of other Jews, helped defeat residual antisemitism on the left.
For Jews, involvement in left-wing politics enabled them to engage in the class struggle, a reflection of the poverty, unemployment, and underemployment that many were experiencing at the turn of the century. As Jews became more prominent on the left, so the left became more concerned about specifically Jewish issues, be they pogroms in the east or Jewish equality in the west.
However, with the exception of the Jewish Labour Bund, the left did not envisage the revitalisation of Jewish national identity. Instead, a utopian assimilationist position was typical, with the "Jewish question" to be "solved" by the triumph of socialist and proletarian culture.
For left-wing Jews, and especially those exiled from Russia, the October Revolution of 1917 represented new hope for global revolution and for Jewish emancipation. Jews returned to Russia to join the Bolsheviks, acting not only as leaders in the Revolution, but being among the very first, like the anarchist Alexander Berkman in his The Bolshevik Myth, to submit the Revolution to a damning, left-wing critique.
Throughout the 1920s, Jews continued to have a greater impact in the Soviet-backed Communist International than their numbers would suggest. Typically, Jewish activists were more likely to be in leadership positions. In the USA, from 1921 onwards, Jews made up about a third of the Central Committee, while in Czechoslovakia as much as 50 per cent of the Communist Party was Jewish. Figures like these, of course, were seized upon by anti-Communist and antisemitic right-wing groups.
The Communist-led International Brigades are central to the popular image of the Spanish Civil War, and the struggle against Franco.
Not all the volunteers were Communists but they were organised by the Communist movement, and represented an important propaganda and political weapon for international Communism. Jews accounted for 45 per cent of the 5,000 Polish volunteers, 38 per cent of US volunteers, and as many as 22 per cent of British volunteers, vastly over-represented considering the size of Jewish communities in those countries. The key role that Jews played in the struggle against Nazism and fascism helped cement, in the mid-1940s, a notable section of the surviving Jewish communities to the left, both Communist and non-Communist.
Just as the prestige of Communism peaked among Jews and non-Jews alike, it became clear that all was not as it seemed.
Increasing evidence of Soviet antisemitism, typified by the "Doctors' Plot", the subsequent purges of Jewish members of the Communist Party of the Soviet Union, and the liquidation of east European Jewish Communist leaders once they had helped install the new Iron Curtain states, struck a massive blow at Jewish support for international Communism.
Even the surprising recognition of the new state of Israel by the Soviet Union, along with its support of UN Resolution 181, was not enough to stop the many Jews moving away from international Communism to Zionism.
The Zionist cause received a tragic boost with the realisation of the extent of the Holocaust. Many Jews concluded that the best hope for Jewish safety lay in Jewish hands alone.
The Jewish Communist movement was effectively at an end, and the USSR became the prime military and political backer of Israel's enemies. But the link with social democracy was not broken. The dominance of the Israeli Labour Party in the first decades of Israel's new existence was matched by strong Jewish-social democratic links in western Europe. In the UK, Harold Wilson, Richard Crossman and Michael Foot were all strongly pro-Israel. At the same time, newly successful Jewish families remembered the poverty and class struggle of earlier generations, and embraced the Labour Party's welfare state.
It would be some time before Jewish electoral support began to move in favour of the Conservatives, a change in which Mrs Thatcher played a large part. Her friend and adviser, Sir Alfred Sherman - the former Communist and International Brigader turned Zionist, Israeli Labour supporter then Thatcherite - embodied a path that many followed.
Today, the Jewish move away from the left has been caused by changes within the global Jewish community and, of course, the triumph of Zionism as an over-arching commitment under which shelters the full range of political standpoints.
Meanwhile, the left has, in the past 40 years, undergone a fundamental shift in its view of Israel. Philip Mendes argues that many on the left care about: "Oppression of workers and welfare recipients, third-world peoples including Palestinians, people of colour, homosexuals and other victims of structural advantage. Jews do not rate highly in this hierarchy of oppression". The electoral pressures on social democratic parties, can make anti-Israeli and anti-Western sentiment a vote-winner in a political landscape featuring growing Muslim electorates.
This is the case with the current British Labour leadership, and much of the activist base of the Labour Party, in which small numbers of Jewish members, and a few Jewish Labour MPs, represent the embers of a once strong relationship. Perhaps more than ever in the divided world of Brexit and Momentum, there is an opening for two parties of the parliamentary left. Only in such a regrouping of UK parliamentary politics might Jewish engagement with British left-wing politics once more be possible on a notable scale.
Matthew B. Hoffman & Henry F. Srebrnik (eds), 'A Vanished Ideology; Essays on the Jewish Communist Movement in the English-Speaking World in the Twentieth Century', (SUNY Press, Albany, New York, 2016).