But he and other Croatian egg producers see little humor in the bills they face. Mr. Sluga estimates that he will have to spend $100,000 on new cages or $13,000 for used equipment. The alternative is to allow his chickens to roam free either indoors or out, something he finds bizarre because, he said, the hens can — and do — eat their own excrement under such conditions. And such an operation would require a lot more labor, he said.

Along the coast, Croatia’s shipbuilders worry that they will not survive either. European Union rules ban state subsidies to most industries, and Croatia is being forced to privatize its shipyards as a condition of entry. In the northern coastal city of Rijeka, trade union officials and managers both argue that not only their jobs are at risk but also the jobs of hundreds or thousands of others who produce components and services for them.

At the 3. Maj shipyard (meaning May 3, the date of liberation from Germany in World War II), 60 employees in a work force of about 2,700 have already left and a further 240 will be lost in a restructuring. But about 450 companies, roughly half of which are Croatian, work with the yard and would be badly hit if it goes out of business. According to Edi Kucan, president and chief executive officer of the shipyard, the company accounts for 1.5 percent of Croatian exports and up to 34 percent of all incomes in the area. The consequence of the shipyard’s closing would be an economic “collapse” in Rijeka, he said.

Yet experts say the process for joining the European Union has been a civilizing factor for a country that has struggled to come to terms with the legacy of atrocities committed in the wars of the 1990s.

Tvrtko Jakovina, a historian at Zagreb University, said that it was a shock when other Central and East European countries, including neighboring Slovenia, joined the European Union in 2004. “It was the first time ever that all Croatian territory was left out of some sort of European integration,” Mr. Jakovina said.

The European Union refused to start membership negotiations until the Croatians helped arrest a former general, Ante Gotovina, who was later convicted of war crimes by a United Nations tribunal.