President Bush’s plan to deploy National Guard troops along the U.S.-Mexico border conjures the image of a war on immigrants.

Rather than treating them like hostile forces, the U.S. government should focus on improving the lives of potential migrants in their home countries. This is no small task, but tackling poverty abroad is the only real solution to immigration concerns.

Europe offers some important lessons on narrowing the gaps. Today, it’s taken for granted that citizens of any European Union country have the right to live and work in any other member state. Achieving this “open door” policy wasn’t easy. When Spain and Portugal wanted to join the EU in the 1980s, there was widespread fear in member states that migrants from these poorer countries would flood northward, stealing jobs and straining public services. At the time, for example, Germany’s average wages were six times higher than Portugal’s.

In response, the EU postponed lifting borders with both countries for five years after they were accepted as members in 1986.

What happened during that transition is key. Determined to narrow the gaps with their southern neighbors, the richer countries poured in aid for infrastructure and work-force training. They also encouraged Spain and Portugal to bolster unemployment benefits and other social protections so that those who were temporarily jobless could continue to seek work at home.

These efforts helped level the playing field so that when borders were lifted, there was no exodus. If anything, the migration flows went in reverse, as thousands of Spaniards and Portuguese who had been working in northern Europe went back home to take advantage of new job opportunities.

In 2011, the EU will be opening borders to 10 additional countries in Eastern Europe, most of them quite poor. The income gaps between Germany and Poland, for example, are nearly as vast as those between the United States and Mexico .

How much can the United States learn from the EU experience?

First, it’s important not to over-romanticize a region that has its own xenophobia problems. Non-European migrants face high entry barriers, and anti-immigrant political parties are on the rise in several European countries.

Second, we can’t expect to simply copy the EU approach. A massive aid fund is a political nonstarter here, even if it were limited to our closest neighbors. Fortunately, however, there are other creative ways to help cash-strapped nations that are major sources of migrants.

One good step would be to expand the U.S. commitment to liberating impoverished countries from the stranglehold of extreme debts. Last year, President Bush joined other leaders in wiping away the foreign debts of 18 countries, most of them in Africa . These countries now can spend funds to reduce poverty and improve health and education rather than make interest payments to global financial institutions.

Other countries should get debt relief as well, particularly those that are both heavily indebted and leading sources of undocumented migrants.

One beneficiary should be El Salvador, which is second after Mexico as a source of undocumented migrants. This small nation is strapped with more than $7 billion in foreign debts (equal to about half the country’s gross national product). As in many other cases, El Salvador’s debts were accumulated in part under a brutal military government. Lifting that burden would give El Salvador a better chance of providing the basic services and opportunities that would reduce migration pressures.

Honduras, the fifth-largest source of undocumented migrants, has even more staggering debts, amounting to 83 percent of GNP. That country has used effectively the limited debt relief that it has already received to provide three extra years of public education for its children. But more help is needed.

Mexico’s some $140 billion foreign debt is one of the world’s largest.

Although the government has made some progress in managing this burden, further debt relief would go a long way towards helping our neighbor eliminate the grinding poverty that drives so many to risk crossing the border.

Once migrants arrive in the United States, they deserve respect for the contributions they make to U.S. society. Given a choice, however, most people would prefer to stay home. The only real solution to migration pressures is to help create the opportunities abroad that will give more people that choice.