At the height of the Arab uprisings last spring, many Europeans were gripped by nightmare visions of a tsunami of migrants crashing against the continent’s shores. The wave never hit, but its specter fed a tenacious anti-immigrant populism that has concealed an important new trend: migration to Europe – and to the United States – has largely stalled. In many countries, more immigrants are leaving than are arriving, owing mainly to the economic crisis that has drained jobs in the West.

That reversal is one of the great under-reported stories of 2011 (and of the preceding two years), and the numbers are startling. Consider Spain, which is on track to lose more than a half-million residents by 2020. By contrast, between 2002 and 2008, Spain’s population grew by 700,000 a year, driven largely by immigration. The trends are similar elsewhere in Europe.

While this fact alone will not quiet opponents of immigration, it does give countries more breathing room to repair and strengthen badly broken systems for receiving and integrating newcomers. Although rapidly aging Western countries are unable to attract the immigrants they need, they allow millions who are already there to suffer discrimination and abuse. Detentions and deportations take place under sometimes terrible conditions. Meanwhile, the international community collectively fails to protect vast populations of vulnerable migrants, such as the millions stranded by the recent conflicts in North Africa.

Undoubtedly, rising anti-immigrant populism must be confronted. While polling suggests that attitudes are influenced more by ethnicity than religion, both help to define identities and mindsets. Political parties in France, Switzerland, and the Netherlands (to name a few) have run successful campaigns that scapegoat immigrants.

Moreover, governments from Alabama to Hungary are passing laws that undermine what should be migrants’ rights. Italy recently adopted harsh “emergency” decrees that target migrants by making undocumented entry and residence a criminal offense.

Anti-immigrant rhetoric from the political extremes has fed into mainstream political discourse. European leaders trip over themselves to declare, one more forcefully than the next, that multiculturalism is dead. Dutch politician Geert Wilders, whose Freedom Party is informally part of the governing coalition, did them one better by being charged with incitement to anti-Muslim hatred. In the US, alligator-filled moats and electrified border fences have featured in the current presidential campaign.

Such attacks on immigration might offer some instant political gratification, but their net result is to cleave societies whose cohesion is already seriously challenged by the economic crisis. Growing discrimination in employment, housing, and education affects not just immigrants and their children; it harms our societies as a whole.

With the lull in net immigration, we now have a window of opportunity to address these shortcomings. Debunking the myths about migration – that most immigrants enter unlawfully, for example, or that immigration displaces existing workers – would be a good place to start. It would also be useful to explain that immigration is necessary for prosperity and growth in almost all OECD countries.

If aging societies in the West and elsewhere (like Japan) fail to get immigration right, they will be woefully unprepared when they confront the real tidal wave: the retirement of baby boomers in the coming two decades. The gaps in these countries’ labor markets – from software specialists to physicians to home health aides – will be immense. The European Union’s labor force will decline by almost 70 million workers in the next 40 years; in the absence of significant net immigration (combined with a much higher retirement age), European economies and social safety nets will shrivel.

The priorities are clear. We need to understand better how our economies will evolve in the coming decades, and to redesign our educational systems to produce workers with usable skills. And, where it is clear that immigrants will be needed, we must be able to identify, welcome, integrate, and protect them.

Meanwhile, our most fundamental institutions – schools, police, and the courts – must be re-engineered to reflect and respond to the diversity of our communities, which is now a fact of life. Countries must learn to work together to achieve these goals, few of which can be reached by going it alone.

If our toolbox were empty, our inaction might be understandable. But examples of smart migration practices abound. Canada and the Philippines, for instance, have a well-functioning accord that protects the rights of temporary workers. Sweden has developed legislation that minimizes bureaucracy for companies that need foreign workers. And important advances have been made in ensuring that immigrant children receive the education that they need to become full members of society.

Progress is being made on the global level as well, despite the economic crisis and populist headwinds. In June, the International Labor Organization’s member states overwhelmingly approved the Domestic Workers Convention, which will significantly increase protections for a vulnerable group of workers – the majority of whom are migrants. Meanwhile, the Global Forum on Migration and Development, established in 2007, has quickly become an important means of fostering knowledge and partnerships.

The reason for growing international cooperation is simple: countries everywhere are affected by migration, and, increasingly, they are experiencing immigration and emigration simultaneously.

Indeed, roughly one-third of migrants nowadays move between developed countries; one-third move between developing countries; and only one-third move from the developing to the developed world. Highly skilled workers, such as bankers and engineers, are flocking to China. Mexico, known primarily as a country of emigration, is home to millions of migrants from Central America. Millions of people in Southeast Asia venture to the Middle East to work, but millions more cross borders within the region. The list goes on.

When it comes to migration, we are all in the same boat – and that boat is leaking. Starting in 2012, countries should redouble their efforts to fix it.