Slovakia and Hungary are embroiled in a diplomatic dispute, after the Hungarian president, László Sólyom, was prevented by Slovakia from entering its territory on 21 August.
Sólyom had been planning to visit Komárno, a Slovakian city with an ethnic-Hungarian majority, in order to take part in the unveiling of a statue of the first king of Hungary, St. Stephen. Since Hungary and Slovakia are both members of the Schengen Zone, there aren't supposed to be travel restrictions between the two.
However, the Slovakian prime minister, Robert Fico, who leads a coalition that includes a radical anti-Hungarian party, has remained unapologetic, saying that Sólyom's visit would have been a "violation of international law and Slovakia's sovereignty".
One reason that the Slovak government has cited for its take on the event is that 21 August happened to be the anniversary of the 1968 invasion of Czechoslovakia by five members of the Warsaw Pact, including Hungary. On top of that, as the Slovak foreign minister, Miroslav Lajčák, pointed out, the organisers of the unveiling of the statue had not invited anyone from the Slovak government to participate.
The Hungarian foreign minister, Péter Balázs, has called his president's denial of entry into Slovakia "unprecedented and unacceptable".
Perhaps the most interesting thing in all this is that both Hungary and Slovakia are Catholic countries, with Catholics accounting for 55% of Hungarians and 69% of Slovaks. St. Stephen, meanwhile, was canonised in 1083. Just a glimpse of how modern nationalism tampers with long-established religious tradition.