One difficulty is the low level of awareness of what's happening in other countries. Owen Jones, visiting Portugal for the Guardian shortly before 30 November, commented that protestors he interviewed weren't aware that the UK was on the eve of a large public sector strike - just as very few people here would know anything about strikes in Portugal. There is, correspondingly, a tendency (even among many activists) to see cuts as basically a domestic issue. This is certainly true here and it seems to be a common weakness elsewhere in Europe.
European elites are acutely aware of the need for co-ordination on their side. There are tensions between them - reflecting the different interets of each national capitalist class - but they continually strive for agreement and common action. They are united in their commitment to making the vast majority of people pay for the crisis through cuts, privatisation and unemployment. Transnational institutions - notably the 'troika' of European Central Bank, International Monetary Fund and European Union - serve their interests.
The crisis is international and cannot be resolved purely at the national level. We need to challenge the international institutions and the power of finance capital. Austerity is a unifying strategy across Europe. The experience of austerity is remarkably similar across the continent: in some countries, like Greece, it is especially severe, but the policies are different only in degree.
Forms of resistance also have a great deal in common. The trademark tactic of 2011 - the mass occupation of public space - is associated with the Arab revolutions, the 'indignados' struggles in Spain and elsewhere, and now the Occupy movement. Several European countries have witnessed mass public sector strikes, primarily a reaction to attacks on public sector workers' conditions but linked to the broader offensive against public services and welfare provision. To some extent, movements in one country have been inspired by movements in another country.
There is, however, great unevenness. That's hardly surprising - each country has its own tempo, reflecting the domestic situation and levels of confidence and organisation in each country. One country's movement has peaked just as another country's has dipped.
The difference in tempo and dynamics across borders is significant. It means that calls for "a European-wide general strike" make - at least for now - little sense. At the European Conference Against Austerity - at the start of October - a German delegate pointed out that such a call might resonate in some countries but not in his own country, where there hasn't yet been a large strike movement.
If there is internationally co-ordinated action, the nature of the action will inevitably vary from country to country. That doesn't mean we can't have co-ordinated action, but simply illustrates the need for realism about how varied such action would be. A European day of action in early 2012 wouldn't translate into a continental general strike, but it could embolden activists throughout Europe and strengthen the connections between them.
Trade unions could play a central role in international co-ordination. From the perspective of UK trade unions, this should be integral to discussion about how to take the movement forward after the large-scale strikes and demonstrations on 30 November. This would build on existing initiatives. The Europe Against Austerity conference was an excellent step by sections of the European left, while the Occupy movement serves as an inspiration to millions.
The conference, held in London, depended on the role of Coalition of Resistance as at least a partially successful attempt to co-ordinate groups at the national level. This national co-ordination is a pre-requisite for ongoing international co-operation. The desperate need for greater international action is in fact one of the main reasons why a bigger and broader Coalition of Resistance is such an urgent necessity.
If the unions co-ordinated their efforts, these developments would become far more powerful. They would gain deeper social weight. The unions can bring millions of their own members into action, through mass protests and strikes, pulling other groups - non-unionised workers, students, unemployed people and so on - into mass mobilisations. International links tend to encourage generalising of the issues too - broad opposition to cuts and privatisation, rather than sectional struggles over specific issues.
The greater the unity and co-ordination, the greater the likelihood of overcoming the divisions fostered by governments across Europe. From dishonest attempts to divide public sector and private sector workers against each other to racist scapegoating, politicians are determined to prevent unity. International action strengthens our side and undermines attempts at divide-and-rule.
International co-ordination tends, also, to have a radicalising effect, drawing attention to the limits of small-scale attempts at reform and the necessity of more far-reaching challenges to the ruling order. Movements begin to raise demands which challenge the core assumptions underpinning cuts, mobilising for financial institutions to be brought under democratic control.
It is only through such co-ordination that we can hope to break the power of finance capital over governments across Europe and re-shape politics away from austerity.