Just arrived in Sarajevo after a bus trip from the Croatian coast. This involves crossing what is possibly the world's most ridiculous border, a sad legacy of the wars that tore Yugoslavia apart two decades ago. In order to reach Sarajevo from Dubrovnik, you have to pass through a six-mile stretch of Bosnia-Herzegovina near the resort town of Neum. The road then takes you back into Croatia, and up the stunning Neretva valley, where you enter Bosnia-Herzegovina again just south of Mostar. The last time I took this road, it was all one country, and there were no borders here at all.

Croatian policemen solemnly inspect your passport on exiting and entering Croatian territory, on either side of Neum. This causes monster traffic jams, particularly at the height of the tourist season in the summer. The Bosnians are more relaxed, casually waving everybody through their six-mile chunk of Adriatic coastline.

If sense prevailed in this part of the world, the nations of the former Yugoslavia would work out some kind of passport-free regime similar to that in use in western Europe, where it is possible to travel freely from one country to another under the Schengen agreement. But having invested so much in gaining their independence, they are reluctant to give up the symbols of sovereignty, however meaningless.

During the Communist period, Marshal Tito decided to award the republic of Bosnia-Herzegovina a symbolic outlet to the sea at Neum, even though the road goes through Croatia. Nobody foresaw then that lines drawn on a map for administrative convenience would congeal into an international border. As things ended up, the Balkans became more balkanized, just as western Europe became more united.

The border crossings at Neum mean that it is impossible to drive to Split from Dubrovnik without passing through Bosnia-Herzegovina. Anxious to create a single stretch of contiguous territory, Croatia has begun work on a $300 million bridge to the Peljesac peninsular that would link the two cities , bypassing Neum. (see map above). There is little economic justification for the expensive bridge, and many environmental arguments against, but this is a part of the world where common sense does not always apply.