One of the major mistakes of the labour movement in the 1960s and '70s in all the developed countries of western Europe and north America was to concentrate on demands for higher wages rather than shorter working hours.
This encouraged employers to switch to large-scale automation and job-cutting, which is the basic cause of the mass unemployment that has developed since the mid-'70s.
It also increased the gap between the working classes in developed countries and those in underdeveloped and poor countries.
As a result, having gone as far as they could in automation and job-cutting in western Europe, the employers began to export factories to poorer countries where wages were much lower.
Far from being a means of encouraging the industrial development of these countries, as some pretended, it was part of the old imperialist tendency of exporting capital instead of goods and so intensified the exploitation of these countries.
The revival of mass working-class activity and international solidarity at the end of the 19th century was around the demand for shorter working hours rather than higher wages.
The whole impetus behind the creation of the Second International was the campaign for an eight-hour day which later, after the first world war, became a campaign for a 40-hour week and holidays with pay.
Barely a quarter of a worker's working hours are needed to produce the goods (value) that pay for their wages. The rest provides the capitalist class with rent, interest and profit and the state with revenue.
An international campaign to cut hours and increase jobs would not only help increase working-class solidarity within each country but also recreate a degree of international solidarity that has faded since the second world war.
An international campaign for a 30 or even a 25-hour week should be a important part of the struggle against cuts and austerity.