"This is it, they're taking us out here to kill us," Stu Russell thought as he trudged through the snow in the middle of the night into a dark forest.

Russell was one of 83 Americans held captive inside North Korea, following the seizure of the USS Pueblo spy ship in international waters, on January 23, 1968.

For weeks they were kept in a sparse, freezing-cold building they nicknamed "the Barn." It had no running water and was infested with rats and bed bugs. Inside, the men were denied sleep, forced into stress positions, whipped and beaten. Their officers, particularly Lloyd Bucher, the ship's commander, came in for vicious punishments, as their interrogators demanded they sign "confessions" stating they were illegally spying in North Korean territorial waters when they were captured.

Like today, 1968 was a period of heightened tensions on the Korean Peninsula. The war that led to the division of the country had only stopped 15 years earlier and bloody skirmishes were still common.

The crew were terrified of the North Koreans. During one interrogation, after Petty Officer Donald McClarren refused to sign a confession, his guard pulled out a gun, put it to McClarren's head and pulled the trigger. The unloaded weapon clicked, and McClarren passed out.

Mock executions like this were routine, as were beatings which seemed like they would never end.

That night in the forest, as Russell shivered and slipped on the icy ground, he became ever more convinced the end had come.

The USS Pueblo seen before its capture by North Korea in January 1968.

Alarm

The seizure of the Pueblo remains one of the most embarrassing incidents in US military history , the first hijacking of a naval vessel since the Civil War, 153 years earlier.

The incident -- reconstructed here from top secret diplomatic cables; CIA, NSA and State Department reports; and interviews with and testimonies from the crew -- raised tensions in the region to near breaking point. Fifty years on, it remains the closest the world came to a second Korean War, one that cables show US generals were prepared to use nuclear weapons to fight, and could have sucked in both the Soviet Union and China.

That the Pueblo's seizure did not result in war was the result of months of careful diplomatic negotiations between North Korea and the US, held in near secret at Panmunjom, the so-called "truce village" on the demilitarized zone (DMZ) between North and South Korea.

As those negotiations dragged on, the crew of the Pueblo were beaten, tortured, and forced to sign increasingly ludicrous confessions, even as they fretted they would face further punishment on return to the US. If they ever got back.

Capture

It was a lousy mission from the start.

After leaving the Japanese port of Sasebo on January 11, the crew of the Pueblo had to deal with equipment failure, frigid weather that meant ice had to be constantly chipped off instruments, and rough seas. When the crew wasn't vomiting from seasickness, they were bored and listless.

Most had little to do as the spy ship's instruments listened in on North Korean communications from international waters, taking special care not to cross the 19-kilometer (12 mile) maritime border claimed by Pyongyang.

Things finally picked up on January 22, when two North Korean fishing ships circled the Pueblo, their decks packed with people straining for a look at the American ship, some holding binoculars and cameras.

Russell was the ship's cook, he came out from the galley to look at the North Koreans. Going to bed that night, he remembers how he remarked "that was pretty exciting today," only to have a more senior sailor smile and tell him "just wait until tomorrow."

He was back in the galley preparing dinner when the North Koreans returned, this time in force.

A heavily-armed subchaser circled the Pueblo and hoisted signal flags: "Heave to, or I will open fire."

The Pueblo responded that it was in international waters as an urgent message was sent warning naval command in the Japanese port of Kamiseya a potential crisis was unfolding.

Four smaller torpedo boats soon joined the subchaser and began circling the Pueblo as two MiG fighter jets flew by overhead. Bucher's ship was hopelessly outgunned, but he was in international waters and he knew other US ships had experienced this type of harassment and escaped unscathed.

As one of the North Korean ships approached the Pueblo with an armed boarding party on its deck, Bucher ordered the helmsman to head out to open sea at full speed.

Russell was outside the comms room when one of the officers inside, seeing him standing there, ran out and pulled him to the floor, screaming the North Koreans were about to open fire.

All four torpedo ships raked the Pueblo with machine guns as the subchaser pumped 57mm shells into the Pueblo's forward masts, knocking out its antennas and sending shrapnel spraying across the deck.

"We need help," radio operator Don Bailey told Kamiseya. "We are holding emergency destruction. We need support. SOS SOS SOS. Please send assistance."

The Pueblo's upper cabins filled with smoke as the crew frantically burned the classified documents on board and smashed equipment with hammers and axes.

Bucher had ordered the ship to follow the subchaser, but seeing there was still a "fantastic amount of paper" to destroy, he told the helmsman to stop, to buy more time. The North Korean ship quickly fired two salvos into the Pueblo's upper deck, seriously wounding two sailors.

Bucher entered the comms room and dictated a message to Kamiseya: "Have been requested to follow into Wonsan, have three wounded and one man with leg blown off, have not used any weapons."

"How about some help, these guys mean business," he continued. "Do not intend to offer any resistance."

The USS Pueblo crew seen in a propaganda photo released by their captors after the ship was seized by North Korea.

Emergency

As the Pueblo was being towed into Wonsan, its crew blindfolded and bound, Washington went into full blown crisis mode. Confusion reigned over why so little reaction had been taken by US forces in the Pacific once they realized the Pueblo was under attack.

Timeline

11 January 1968 Pueblo departs Sasebo, Japan

22 January 1968 Two North Korean fishing boats circle the Pueblo

23 January 1968 Pueblo attacked and captured by North Korea

26 January 1968 President Johnson addresses the nation

2 February 1968 US and North Korean negotiators meet at Panmunjom

4 September 1968 US cable warns Panmunjom negotiations "at an impasse"

12 September 1968 North Koreans stage press conference with Pueblo crew

23 December 1968 US signs North Korean-drafted apology

Pueblo crew released across the DMZ

24 December 1968 Pueblo crew fly back to the US



Source: NSA, US State Department, George Washington University



As a damning US congressional investigation later found, "no effort was made by the Navy to launch aircraft from the USS Enterprise," a carrier around an hour's flight from the Pueblo, nor was any attempt made to launch jets "from any of the numerous bases in Japan which were the closest source of possible assistance."

What planes were scrambled to help were launched from Okinawa, more than 1,400 kilometers (890 miles) away, and they lacked the fuel to make it to the Pueblo in one go. By the time they refueled in South Korea, it was too late.

As President Lyndon Johnson and his advisers struggled to get on top of things, they advised the government in Seoul "in strongest terms" not to attempt any action which could endanger the Pueblo's crew.

This was a distinct possibility as, days before, North Korean assassins had come within 100 meters of the Blue House, South Korean President Park's official residence. The two countries were still technically at war (as they remain today) and as the Pueblo was being captured, South Korean commandos were busy hunting down and killing the remaining North Korean hit squad.

Even as Washington urged caution in Seoul, the US military was told to prepare for forceful action, and 12 different military solutions were drawn up , including sailing a ship to the same location where the Pueblo was seized in a show of defiance, bombing North Korean bases and airfields, and dropping anti-ship mines into its major ports.

Ultimately, Johnson rejected all active military options, choosing instead a "show of force," ordering hundreds of US combat aircraft and an armada of 25 warships, including three aircraft carriers, to South Korea.

As a top secret cable warned, "once the US took retaliatory actions involving the use of military force against North Korea ... the chances of obtaining early release of the crew and ship would be virtually eliminated."

"Moreover, retaliation would probably bring the Chinese and Soviets more directly into the situation," the memo said , adding "the risks of an enlargement of the crisis and actual hostilities would be increased."

Top secret files recovered from the USS Pueblo seen in a propaganda photo released by North Korea.

Hostages

Arriving in Wonsan in the aftermath of the initial capture, the Pueblo crew were divided into two groups and, still blindfolded, loaded into vehicles. They were taken to a train station, where a large crowd of people who had gathered yelled anti-American slogans, spit on and hit the crew members. After almost 10 hours on the train, the crew reached Pyongyang and "the Barn."

From the moment their ship was boarded onwards, one of the most disturbing things for the crew was the North Koreans "total and complete hatred" for the US crewmen.

"You could just feel it," Russell recalled in an interview with CNN. It bewildered the young Americans, many of whom "had no thoughts about North Koreans one way or another."

It wasn't until much later he learned of US activities during the Korean War: "We'd bombed the crap out of North Korea, killed over one third of the population. There was no family in North Korea that hadn't lost close relatives because of America."

This hatred — which previously manifested itself in random violence and cruelty — made it all the more likely to the crew that their North Korean captors would eventually execute them.

On that night in the snow, Russell had visions of Nazi mass graves, Poles, Russians and Jews shot and bundled into hastily dug holes by the SS. But after what felt like an eternity of walking, the men came upon a small building. Inside were taps and buckets of water for the men for the men to wash themselves with.

The North Koreans had no intention of killing their hostages: the seizure of the Pueblo had been a major propaganda victory for Pyongyang, and forcing the US to grovel to get its men back would make it even better. The crew was moved to another location — "the Farm" — where things got marginally better. They were told they would be kept there until the US apologized.

The crew thought this was impossible, but unbeknownst to them, after months of futile negotiations at Panmunjom, Johnson's administration was preparing to do just that.

The iconic blue huts in Panmunjom, on the DMZ between North and South Korea, seen in 1965.

Negotiations

Following the end of the Korean War in 1953, a four-kilometer (2.5 mile) wide, highly fortified demilitarized zone (DMZ) was set up between the two countries. In the center, sits the Panmunjom Joint Security Area, where South and North Korean soldiers stand watch meters away from each other.

Almost 65 years since the end of the war, the situation remains basically unchanged

Blue huts straddle the border, and it was here that negotiations began on February 2, 1968 . Early meetings were dominated by North Korean demands for an official apology and American insistences the Pueblo was in international waters and had done nothing wrong. Progress was slow but businesslike, with North Korean Maj. Gen. Pak Chung Kuk often reading from a stack of statements apparently prepared for any potential US gambit.

The negotiations stretched on for weeks and then months, as the crew of the Pueblo were tortured and hawks in both Washington and Seoul urged military action. Tensions reached such a height that during this period, Adm. Ulysses Sharp, commander in chief of all US forces in the Pacific, drafted a top secret plan to defend South Korea against a possible second invasion by the North.

In one scenario, dubbed "Freedom Drop," US planes or ground forces would hit attacking North Korean troops and tanks with nuclear explosives while nuclear-tipped missiles with yields of up to 70 kilotons, more than triple that of the atomic bomb dropped on Nagasaki, would strike key targets inside North Korea.

The USS Pueblo seen in Pyongyang, North Korea, on April 16, 2001.

CIA report around this time concluded that, while North Korean guerrilla and cross-border activity had increased dramatically and was continuing, Pyongyang did not intend to invade or risk a full-scale war. However, the CIA warned South Korea's President was becoming increasingly frustrated with both Pyongyang and Washington, and the risk of him, not the US, ordering a "large-scale retaliation" was increasing.

The unpredictability of the South Koreans throughout this process was shown in June 1968, when North Korean forces attacked and sank a covert South Korean reconnaissance boat. Seoul's disastrous spying mission was planned and executed without the knowledge of US Army Gen. Charles Bonesteel, who, as commander in chief of United Nations forces in South Korea, was nominally in charge of the country's navy. In a cable to Washington, Bonesteel warned the South Korean spy mission could have jeopardized the Pueblo negotiations. The mission, Bonesteel said, "fed Communist propaganda which aims to prove to the world that UNC and ROKS are the provocative aggressors."

By September 1968, negotiations at Panmunjom had reached "an impasse," according to a declassified White House memo.

Eventually, following a press conference staged by the North Koreans with the crew of the Pueblo, which ended with Bucher calling on the US government "to do something to save the lives of these young men," Washington agreed to sign an apology as Pyongyang demanded, provided it be allowed to issue a statement beforehand.

The document , presented by Pak to negotiator US Army Maj. Gen. Gilbert Woodward, was addressed to the "Government of the Democratic People's Republic of Korea," a term never used before by the US, which did not recognize Pyongyang's legitimacy, and said the Pueblo "illegally intruded into the territorial waters of the DPRK ... and conducted espionage activities of spying out important military and state secrets."

Freedom

Even as negotiations were reaching a breakthrough, the men of the Pueblo came close to dooming themselves.

One night, after being shown two North Korean propaganda films in which Westerners were seen raising their middle fingers to the camera, the crew realized their captors didn't know what the insulting gesture meant, and started flipping them off at every opportunity, including in staged photos and films.

When the North Koreans realized what they were doing -- thanks to US media reports on the protest -- they were enraged. As a lawsuit brought by some of the crew against the North Korean government recounted, their captors "began a campaign of beatings, harassment, and interrogations so intense and concentrated that the hostages referred to it as 'Hell Week'."

The USS Pueblo crew display their middle fingers in propaganda photos put out by their captors.

"They were subjected to cold temperatures, open doors, constant surveillance, lights on at night, sleep deprivation, and a more rigid enforcement of all rules," the lawsuit said. "They were required to sit in a chair at all times with their heads bowed unless they had specific permission to do otherwise."

Then, suddenly, everything changed again. The men were given new clothes and told they were about to be released. The US had agreed to apologize.

On December 23, 1968, at 9 a.m. Seoul time, Pak and Woodward met for the last time. Woodward read out a short statement denouncing the document he was about to sign and saying he only did so to free the men of the Pueblo. Then he signed it.

On the North Korean side of the border, the crew were sitting in two buses, wearing new clothes given them that morning. The temperature was frigid, and the moisture from their breath turned to ice on the windows as they waited for several hours.

The USS Pueblo crew cross the Bridge of No Return between North and South Korea, after their release into US custody on December 23, 1968.

Eventually, at 11:30 a.m., the men crossed the "Bridge of No Return," which spanned the DMZ. They came in single file, led by Bucher, who was followed by two crew members carrying the body of Duane Hodges, who had died as a result of a wound sustained during the attack on the Pueblo.

As he crossed into South Korea, Russell thought "this is the greatest day of my life," but his face, like those around him, was largely devoid of emotion, his spirit "beaten down so far, and trying to come back up."

It was 11 months to the day since the Pueblo was captured.

Once in South Korea, the men were led to an army base and ate "one of the finest meals" they'd ever had: coffee, orange juice, ham sandwiches, and chicken soup. They were helicoptered to a base near Seoul for medical check ups before finally, on December 24, flying back to the US and their families, just in time for Christmas.

The USS Pueblo itself was never released. It is still an officially commissioned US Navy ship , one of the oldest in the US fleet. Since 2013, it has been used as a tourist attraction and propaganda museum in Pyongyang.

The USS Pueblo crew greet relatives upon returning from captivity in North Korea.

War

Multiple top secret US cables and reports testify to how close the Pueblo crisis brought the Korean Peninsula to a second war.

In the 13 months prior to the Pueblo incident, there were 610 violations of the armistice agreement by North Korean troops, 200 of whom were killed while the wrong side of the DMZ. At the same time, North Korea repeatedly complained of "infiltrating naval craft and armed espionage vessels" along its coast, threatening retaliation.

"Any idiot could tell things were escalating," Russell told CNN recently. Things only got worse following the Blue House incident, of which the crew of the Pueblo were never informed.

"They should have told us to get the hell out of there, and they didn't," Russell said.

A scathing report by the Congressional Committee on Armed Services largely agreed, criticizing the planning of the mission, the lack of support or protection for the Pueblo, and the "absent or sluggish response by military commanders" once the crisis got underway.

"The Navy had no contingency plans whatsoever to provide for going to the rescue of the USS Pueblo in an emergency," the report said.

Noth Korean leader Kim Jong Un salutes as he walks in front of the USS Pueblo in Pyongyang on July 27, 2013.

The history of the Korean Peninsula since the war which split it is littered with incidents like the Pueblo, though the ship's seizure was by far the worst. At times of the greatest tensions, communication has been cut off between Pyongyang and Seoul and Washington, leaving all parties to guess at what the other's intentions are.

A repeat of the Pueblo incident today would be even riskier, with North Korea possessing a nuclear arsenal Kim Il Sung could have only dreamed off, and pressure building in Washington to take pre-emptive military action against it.

Ultimately, what avoided war in 1968 could be what avoids it today: sitting down and talking. This month, North and South Korea did just that, reopening communication lines for the first time in more than two years.