The symbolism of the top local film at South Korea's box office, Heaven's Soldiers, could hardly be more timely. The unlikely plot has North Korea and South Korea developing an atomic weapon, when Washington demands a halt. The North escapes with the plans but a freak accident sends them back in time with their South Korean counterparts. In the 16th century, they team up to aid Korea's greatest historical hero, Admiral Yi Sun-shin, as he repels invaders from Japan and Manchuria. The movie's plot underlines a growing pan-Korean sentiment that shows Washington must tread delicately around Korean sensibilities. Increasingly, Seoul will find it harder to back tough talk from the US. 'Hollywood heroes Batman and Superman - Get out!' blares the marketing of Heaven's Soldiers. 'Our Korean hero, Yi Sun-shin, will save us!' A pan-Korean nationalistic genre was kick-started by a best-selling novel of the early 1990s. The Rose of Sharon is Blooming imagined South Korea, under attack from Japan, being saved by a nuclear-armed North Korea. The rose of sharon is Korea's national flower; many young South Koreans today see no reason why Koreans should not possess the bomb. Even the late US general Douglas MacArthur - saviour of the South from the Northern invasion in 1950 - is not inviolable. Two weeks ago, protesters called for the removal of MacArthur's statue from Incheon, scene of his famed amphibious landing, saying that Korea had been under 'Yankee' domination for far too long. While such sentiments are not mainstream - anti-MacArthur protesters were outnumbered by pro-American protesters, and Heaven's Soldiers was in third place behind Hollywood imports - they are widespread. Meanwhile, the two Koreas have been cementing ties following the meeting between North Korean leader Kim Jong-il and Seoul's Unification Minister Chung Dong-young on June 17 in Pyongyang. 'The general mood in South Korean society towards the North has ameliorated,' said Dr Park Young-ho of the Korea Institute for National Unification, a think-tank. 'There is a segment that believes we can allow the North to go nuclear.'