From May 1, when 10 more countries join the European Union, the EU will have a new eastern border. Poland will be policing much of that border, and it is trying very hard to make sure that EU requirements for a tightly controlled frontier do not unnecessarily disrupt the lives of its Ukrainian and Belarussian neighbors who have traditionally crossed into Poland to work and trade.

The EU has given the former communist countries that will join the bloc next Saturday hundreds of millions of dollars to beef up border posts and buy patrol vehicles, helicopters, night-vision equipment and computers. They are now charged with stopping potential terrorists, drug smugglers and illegal immigrants from trying to enter their territory and use it as a bridge to more prosperous EU countries.

Poland, the biggest of all the newcomers, will patrol nearly a third of the EU's 3,800 kilometer eastern border, and it says it is ready for the job.

The Poles have doubled the number of guards and turned their border police from a conscript force into a professional one. Watchtowers are now spaced 21 kilometers apart, whereas a few years ago they were nearly 100 kilometers distant from one another.

Many Poles feel a bit uncomfortable with their country's new role as the EU's eastern guardian because it hampers the close cultural, personal and family ties that bind them to people in Ukraine and Belarus.

People from those countries used to enter Poland by showing their passports. But, under EU regulations, they now need visas. Pawel Swieboda, the head of the Polish Foreign Ministry's Europe Department, says his country has tried to reassure its neighbors by issuing free visas to Ukrainians and inexpensive ones to citizens of Belarus.

"We have worked together to find ways of making life easier in the new circumstances," says Mr. Sweiboda. "For example, we have put in place an extremely flexible open visa regime within which we don't charge the Ukrainians for the Polish visas. In return, they decided not to require visas from our citizens."

Mr. Swieboda says Poland is a magnet for Ukrainians in the same way that Germany and the West have been for Poles, whom, he says, learned about political freedom and market economics there and brought those ideas back home in the 1980's. "We are hoping that the same scenario will materialize for Ukraine," he says. "That the Ukrainians would come here, see how Poland is changing, how it is transforming its economy, its political life, and that this power of example will be very influential in how Ukraine sorts out its problems."

It is a major tenet of Polish foreign policy that the EU should not close its doors to eventual membership for Ukraine and Belarus. That view is also shared by some of the other new member states, who are pressing for a debate on the Union's future borders, a debate existing members shy away from because of the one-man rule of Belarus President Alexander Lukashenka and what they see as the corrupt and entrenched power structure in Ukraine.

Still, EU enlargement commissioner Guenter Verheugen says he foresees a big push for a closer relationship between the EU and its new eastern neighbors. "We now have member states which have very old, traditional and, sometimes, very difficult relations with our eastern neighbors - with Russia, Ukraine, with Belarus, which is today a black hole in the European system. And I'm absolutely sure that our new member states will put a lot of pressure on us to develop a kind of eastern dimension to the European Union," says Mr. Verheugen. "At the end, that would mean that we would have a free trade area with one billion consumers - by far, the biggest in the world."

Average salaries in Poland are five or six times what they are across the eastern border. Tens of thousands of Ukrainians are living and working in Poland, most of them illegally. But Polish police have not made a big effort to hunt them down and deport them.

Analyst Lena Kolarska-Bobinska, who heads the Committee on Public Affairs, a major Warsaw think tank, says Ukrainian immigration is needed in Poland, in part to replace the Poles who have gone West seeking higher paying jobs themselves. "We are not afraid of migration to Poland because many Poles find Ukrainians working here as a very useful support on the labor market," she says. "Like with Poles in England or Germany, those migrants are [a] qualified?labor force which is, very simply, cheap. And they are rather afraid that, with the new EU regulations, this migration will be much smaller and much more difficult for the Ukrainians."

One of Poland's new responsibilities as an EU member is to stop the flow of contraband from Ukraine and Belarus. Before the visa regime was imposed last October, Ukrainians made a living by crossing the border several times a day carrying the two cartons of cigarettes allowed by Poland on each crossing. Border police say that they now stop anybody crossing repeatedly in the same day.

But, as Commander Marek Dominiak of the Polish Border Guard told a seminar in Brussels recently, such petty smuggling is bound to continue. "There's always a segment of the population that makes a living on illegal trade, several kinds of illegal trade. Some goods are brought simply illegally," he says. "Others are smuggled across the border outside the border passes, and there are always people who have traditionally been making their living, and due to the differences in prices in the European Union and the countries outside, I'm sure this will still persist, so this is something that we can't totally curb."

Commander Dominiak says his men will try to strike a balance between preventing smugglers of arms, drugs and illegal immigrants from entering the EU and keeping life tolerable for locals on both sides of the border.