For a guide to just how important trains are to South Korean strategic thinking, think of the country as a virtual island. On three sides is ocean. On the northern side is the 249km border with North Korea, one of the most fortified stretches of land anywhere. Nothing gets across it with any regularity, aside from passing flocks of migratory birds. South Korea is an industrial powerhouse, yet its island status means goods and materials have to be shipped or flown in and out. A fully functioning connection to the trans-Siberian railway would, for example, slash shipping times to Europe - one of its major markets - by two thirds. Large government billboards outlining such a vision flank big avenues around Seoul. The eventual realisation of that vision took a step closer to reality this week, buoyed by the recent summit between North Korean leader Kim Jong-il and his southern counterpart, President Roh Moo-hyun. Defence ministers from the North and South agreed to a daily cross-border train service to the Kaesong Industrial Park just inside the northern border, starting on December 11. Working-level officials are set to meet on Tuesday to thrash out an agreement on including Kaesong as part of a more substantial route running between Munsan in the South and the North's Bongdong, a 20km route severed during the Korean war in the early 1950s. No one is pretending the moves represent a breakthrough, but there is palpable relief in the minds of South Korean officials after years of dashed hopes and false starts in their dealings with the Stalinist hermit state. The initial test of the Munsan line in May was met with considerable fanfare, with media from Seoul reporting the effort had cost the South an estimated US$500 million - making the test the most expensive train ride in history. Hopes for follow-up tests swiftly evaporated, however. Ever paranoid, Pyongyang yet again cited unspecified security fears as a reason for more delays. Those issues are expected to surface again this week, but there are broader hopes for meaningful progress. 'There is a sense now that the North is more comfortable with the idea of train connections,' said one official in Seoul. 'Kim Jong-il gave clear signs of this at the summit in October so now we've got to make sure we can seize the moment.' Even if the Munsan line and another route further east prove problematic, the Kaesong link remains highly significant. When the industrial park opened in 2004, Kaesong was supposed to herald a new era in North-South economic co-operation, with South Korean firms using the zone to hire low-paid but talented workers from the North. Infrastructure problems and bureaucracy have thwarted benefits that included tax inducements. The number of workers employed is still beneath 20,000 - a far cry from the 100,000 targeted at the opening. The new route offers potentially easier access to materials and fresh hope of improved productivity, but quite how customs relations work in practice remains to be seen. Even if there is fresh progress on co-operation in the next few months, a mammoth challenge lies ahead. Like much of its remaining industrial infrastructure, bankrupt North Korean railways struggle to function. Rusting, idle, steam-driven locomotives dot the countryside, recent visitors report. Government studies suggest upgrades to create a proper North-South link-up through the country could cost upwards of US$2 billion in fresh investment. As officials plot their next round of talks, one thought intrigues them. Trains, of course, are Mr Kim's favoured form of travel. His last recorded trips to the mainland and Russia saw him leave the country in one of his specially-armoured trains, complete with a silver service dining car and tanks of fresh lobsters. 'At least we know we are talking about something close to the Dear Leader's heart,' one Seoul official said. 'Maybe that is one of the problems.'