But they were exposed anew this week in absurd fashion.
A journalist based in Republika Srpska, the predominantly Bosnian Serb half of the country, was badly injured in a traffic accident last weekend while returning from a commemoration ceremony at a former Serb-run detention camp for Bosniaks and Croats where many people died early in the 1992-95 war.
He was transported to a clinic in Banja Luka and prepared for an operation on his fractured hip.
But it soon became clear that the hospital didn't have sufficient supplies of his blood type, and his bureau colleagues in Sarajevo, the capital of Bosnia and its Muslim and Croat federation, volunteered to donate blood.
When they arrived at the Transfusion Institute in Sarajevo, however, they were stunned to hear that administrative barriers prevent donated blood from being sent to the other part of the country (ie, the Muslim and Croat Federation) without a special request, which did not happen in this case.
The only way they could quickly help their injured colleague was to go to East Sarajevo, a "city" formed from the capital's prewar suburbs that the 1995 Dayton peace agreement placed in Republika Srpska, and donate blood there. Which they promptly did.
The operation was successful and the journalist now faces a long convalescence.
The episode raises questions about the unity and viability of a country whose most optimistic officials hope can achieve candidate status for membership in the open-bordered European Union by the end of this year.
"It's not just blood, it's the medical practice in general," says Midhat Haracic, the Muslim head of the Sarajevo-based Transfusion Institute. "People travel, get hurt.... It's unbelievable that a system like this is in place, because it strengthens divisions."
His words are echoed by a Bosnian Serb surgeon and state parliamentarian, Lazar Prodanovic. "EU directives oblige Bosnia to offer full health coverage everywhere, just like it is offered on the territory of all member states," he says, "and it would be absurd for us to have barriers."
Bosnia has come a long way since the guns fell silent in the winter of 1995 after 3 1/2 years of war among its predominantly Muslim Bosniaks, Orthodox Serbs, and Roman Catholic Croats.
Thanks to the strong involvement and presence of NATO and EU peacekeepers and mainly U.S. and EU peace officials in the first decade after the war, the three isolated communities created a host of joint institutions on a state level.
For example, the country has a single central bank and stable currency, a joint military, law enforcement and intelligence agencies, and a state court prosecuting corruption, organized crime, and war crimes. All Bosnians may move freely around the country and use one set of identification documents.
Bosnia even has single national teams in all sports, with athletes from all three groups.
But the two autonomous "entities" still have broad autonomy and authority in areas such as the economy and policing, but also in education and social and health care, and it appears that most Bosnian Serbs would like it to stay that way.
The region's president, Milorad Dodik, of Dr. Lazar Prodanovic's Alliance of Independent Social Democrats, has in recent years fiercely opposed any attempt to remove barriers between the regions and strengthen the state, and he has even advocated returning some competencies to the respective entities.
"Even when we talk about the disabled, we say, 'These are ours, I don't care about theirs.' That kind of segregation is rooted in the system, in the constitution, in the Dayton peace agreement -- and it is obvious that it cannot function that way. That's a catastrophe, that's anti-human," says Besim Spahic, a professor at the Sarajevo faculty of political sciences.
Almir Cehajic Batko, a popular talk-show host at Radio Kameleon, says one can't even donate funds to a humanitarian campaign by calling the mobile number of an operator from the other part of the country.
"The answer you get is, 'The dialed number is not in use.'"
-- Nedim Dervisbegovic, based on reporting by Dzenana Halimovic