But in the case of the Koreas, it is football, not table tennis, that is easing open long-closed doors. Some 37 members of a South Korean labour federation left for Pyongyang, the North Korean capital, yesterday for an officially sanctioned, friendly soccer match, the first between the rival Koreas.
"Workers should take the lead in advancing reunification of the Korean peninsula," members of the Korean Confederation of Trade Unions (KCTU) chanted before boarding a plane to Peking and from there to Pyongyang.
Thursday's soccer match against North Korean workers is part of the celebrations leading up to 15 August, which both countries celebrate as "Liberation Day", marking the end of Japanese colonial rule after the Second World War.
South Korea bans visits to the North, except by special permission, which was given for the football match. A KCTU spokesman said a delegation from North Korea was due to go to South Korea next year to hold a similar match in Seoul.
Meanwhile, five South Korean student and dissident leaders arrived in Pyongyang on Saturday on an unauthorised trip to take part in reunification festivities sponsored by North Korea. The South Korean prosecutor's office said they would be arrested on their return.
North Korea's official Korean Central News Agency quoted one of the dissident leaders, Ra Chang-sunm, as pledging not to "throw away the banner of unification and patriotism though the way of reunification and patriotism is thorny".
In past years, South Korean students and workers have clashed with police when they tried to march to the border for a pro-unification demonstration on Liberation Day. South Korea has banned such rallies.