He was once despatched to assassinate a South Korean president, but Kim Shin-jo was delighted at last week's inauguration of conservative Lee Myung-bak in Seoul. 'There has been something wrong in our society,' Mr Kim, 67, said of the past 10 years of liberal rule in Seoul. 'I believe Lee will defend freedom.' The sole survivor of a North Korean commando squad given the task of 'cutting the throat' of then-South Korean president Park Chung-hee in 1968, Mr Kim, today a Presbyterian pastor, is a fierce critic of the engagement policy pursued by the previous two Seoul administrations. 'North Korea has not been 'engaged',' he thundered at his office in a Christian retreat among hills overlooking the frozen Han River, north of Seoul. 'Nothing has changed in the regime or the military: South Korean support has only made the regime stronger.' He should know. Mr Kim grew up in a staunchly communist family in North Korea. At 24, during his military service, he was selected for special forces. 'I realised I was undertaking a revolutionary mission,' he said. 'My life was no longer guaranteed.' Training was gruelling. They learned weaponry, navigation, parachuting, amphibious infiltration, camouflage. One concealment tactic was to dig into graves and hide. 'We slept with the bones: It made you fearless and nobody would think of looking for you in a grave.' They swam rivers and ran up mountains. Carrying 30kg packs, they ran at 12km/h cross country. Sometimes they were starved and forced to eat roots, snakes and frogs. Some men lost toes, fingers and even feet to frostbite in winter. Martial arts were emphasised: on his left hand and arm Mr Kim still bears scars from knife fighting. 'I was a southpaw,' he explained. His first cross-border operation was a reconnaissance of a US radar installation. The mission was successful: he returned without detection. His next operation would be a different matter. The year 1968 would prove the fiercest of the Asian cold war. In Vietnam, it would be marked by the Tet Offensive. In Korea, the US spy ship the Pueblo would be seized. Before those events, in January, Pyongyang's high command planned an audacious operation to reunify the peninsula under communist rule within days. 'It had to be a short-term war,' Mr Kim said. 'In the Korean war, North Korea could not win due to lack of money, lack of resources. The strategy was to win before US aircraft from Okinawa could arrive. It had to be a swift, asymmetrical attack.' The plan was to assassinate the South Korean president. Media reports of Park's death, Mr Kim claimed, would signal other North Korean commando units to go into action - by parachute landings, amphibious infiltration and foot infiltration across the border. Ministries and key US and South Korean military bases would be attacked, prisons would be opened, spreading confusion. Commandos with special equipment would take over broadcasting stations and post offices. Pro-North Korean elements in the south were to rise on January 22 and the headless government would collapse. 'It would be like a revolution from within,' Mr Kim said. The unit chosen to spearhead the operation was the crack 124th Special Forces - Mr Kim's unit. Three assault teams would attack the presidential Blue House in central Seoul. Mr Kim, a lieutenant at the time, would lead a group that would clear the first floor. The unit's commander would lead his team onto the second floor and execute Park. The third group would provide cover. Three men would commandeer getaway vehicles. 'We were confident,' recalled Mr Kim. 'We knew all about the Blue House defence; we didn't think much of their bodyguards.' At 4am on January 18, 1968, 31 commandos crossed the border. They wore South Korean uniforms and were trained in Seoul accents. 'This is the basis of guerilla fighting,' he said. They removed mines as they went. They halted before a South Korean observation post, where women were going in: 'They were not very alert.' Covered in white sheets, the would-be assassins crossed the frozen Imjin River. Moving at night, they avoided patrols, but resting on a forested hillside, were discovered by a group of poor loggers. Mr Kim suggested killing them - 'by the book' - but his commander, Kim Jong-moon, who had led seven cross-border operations, let them go free. 'At that point, I thought our mission would fail,' Mr Kim said. After dark, the men moved out. Before long, they became aware of trucks and buses moving. The loggers had alerted the military. 'They blocked the roads, but they could not stop us,' Mr Kim said. 'They thought we would move at 8km/h, but we moved at 12km/h. They blocked the roads behind us: We had already passed through.' It was freezing and the South Korean soldiers sent out to hunt them lit fires, giving away their positions. The commandos easily avoided them and crossed the Seoul ring road. They laid up in the mountains overlooking the city. Below was a bus terminal. The objective was within reach. Gazing over the suburbs, Mr Kim had one surprise: Seoul, which he was told would be blacked out due to electricity shortages, was glittering. The men hid their uniforms and dressed in Japanese civilian clothes they had carried with them. Their personnel weapons - automatic rifle, 350 rounds, 14 grenades, pistol, dagger - were concealed in waist bands, and covered with trench coats. Thus armed, the assassins entered the city three days after they had crossed the border. Seoul was crawling with military and police. 'We were stopped by police,' Mr Kim said. 'They said, 'Who are you?' We said, 'Capital Intelligence Command. We are on an operation!' They let us go on.' But at about 10.30am, 200 metres short of their objective, they were challenged by a local police chief. This time their bluff did not work: he demanded ID. The commandos drew their weapons, mowing down the police officer and his jeep driver. Then they attacked. The Blue House, however, had been reinforced. Outside its front gate, the commandos ran into a defence platoon armed with automatic weapons. A furious firefight broke out. Incongruously, a bus drove through the crossfire. It was peppered with bullets, the women and children aboard killed. Then tanks rumbled up. The commandos had no way to take on armour and they scattered. Most headed north. Mr Kim broke east. Suddenly he was surrounded. 'I put my weapon down. I had a desire to live: it's the basic instinct of humans.' Of Mr Kim's unit, 29 were hunted down and killed over nine days. One escaped. Sixty-eight South Koreans and three Americans also died. For one year, Mr Kim was interrogated. No violence was used. The South Koreans must have realised that would have been counterproductive. 'I had high self-esteem,' Mr Kim said. He told his captors everything they wanted to know. Then he was put on trial, where it was proven that his weapon had not been fired. 'In the firefight, I only had one concern - to survive.' On 10 April, 1970, he was freed to enter society. He found work in construction and lectured to the South's army on the North's special troops. In October that year, he married a Christian who had written to him while in captivity. The couple had two children. But life proved difficult. He learned that his parents had been executed after his defection became known. In the market, his wife was pointed out as the 'wife of the North Korean spy'. His children faced trouble at school; Mr Kim's story was featured in textbooks. He attempted suicide. On her birthday in 1980, his wife asked him to join her at church as his present to her. Mr Kim consented as Christianity intrigued him. As he learned more, he said, he found peace. In 1995, he became a pastor. Today, Mr Kim preaches at a religious retreat outside Seoul and counsels North Korean refugees in the South. He has written four books. One, referring to the fact that he can never return home, is entitled, The Wild Goose that Cannot Fly North. 'I pray for both countries,' he said. Mr Kim hopes that South Korea's new president will take a tougher line with the North than his predecessors. Like many defectors, he believes that Seoul 'has been driven, exploited and used by North Korea'. He remains suspicious of Pyongyang, which lacks hi-tech military assets but retains dangerous unconventional warfare capabilities. 'It took the South Korean Army nine days to track down my unit. What would they do if all the North Korean special forces came South?' he asked. 'There are 100,000 like us. Only when all special force units are disbanded can we say the North has given up its intention to communise the South.' And that disastrous mission, 40 years ago? 'I try not to think about it,' he said. 'It still fills me with horror.'