The deportations began yesterday. Two flights left France, bound for Bucharest, with 93 Roma immigrants on board. Some 700 Roma are expected to be removed by the end of August. And 300 illegal Roma camps in the country will be demolished over the next three months. The explanation of the French government for the deportations is that the camps have become bases for people-trafficking, prostitution and crime. But critics of the policy detect an uglier motive: a hope from President Nicolas Sarkozy to distract public attention away from allegations of corruption that swirl around his administration.

If true, this would be nothing new. Immigrants often find themselves made into scapegoats, especially at times of economic stress. And France is by no means alone in this respect. The Italian state has been harassing and deporting its Roma migrants for several years now. A legal battle is raging in the US over a law passed by the state government in Arizona giving police the right to demand that individuals show their identification in order to detect illegal immigrants from Mexico, something that opponents say has resulted in racial profiling. Popular concern about the children of illegal immigrants in the US has also led to some suggestions in Republican circles that the constitutional provision that grants citizenship to those born on US soil should be revoked. Meanwhile, the two candidates in the Australian election, the Prime Minister, Julia Gillard, and Tony Abbott of the opposition Liberal Party, are locked in competition over who can adopt a tougher line on the "boat people", a reference to the desperate asylum seekers who make for Australia's shores by sea.

The hypocrisy of all this is rich. In Australia, Ms Gillard and Mr Abbott are both immigrants themselves, the Prime Minister having been born in Wales and the opposition leader in London. President Sarkozy's father was a Hungarian aristocrat who fled to France in the wake of the Second World War.

But the hypocrisy is not confined to politicians. Most economically advanced nations – Australia and America above all – have been enriched by migrants. To see the citizens of such countries turning on those who hope to follow their path – a path which history shows is generally to the benefit of the migrants and the host country – is depressing indeed.

Yet, however unpalatable they are, these public pressures are real. The question is: what should be done to counter them? A return to economic growth would help. When people are economically insecure they tend to be much more susceptible to the demagogues who peddle the simplistic and false notion that less immigration will mean more prosperity.

But the primary response has to be political. Democratic leaders need to be prepared to stand firm against xenophobic impulses, rather than pander to them. Where there are legitimate grievances over stresses imposed by migration patterns on public services, they must act to ease the burden. But that must not be confused with punishing or harassing immigrants themselves. Politicians also need to be prepared to explain to their electorates that immigrants, with their skills and their labour, are essential to helping our economies return to health.

Sadly, Britain can hardly be said to be setting much of an example in this respect. Our own government intends to impose an annual cap on the number of migrants who can enter the country, even though its own economic watchdog, the Office for Budget Responsibility, says this is likely to restrict growth.

The global economy remains weak and xenophobia is likely to remain a potent force in democracies around the world. Responsible political leaders everywhere need to summon the courage to explain to their citizens that immigrants are not the cause of their problems.