Pyeongchang, South Korea -- at every Olympic Games, safety is a top concern, with athletes and spectators scattered across the field and hard to protect. But few have been played out in the shadow of a nuclear confrontation like the winter Olympics in South Korea next week.
Nearly 3,000 athletes from 92 countries and 100,000 spectators a day will gather around pyeongchang, 50 miles from the north Korean border, in what organizers say will be the largest winter Olympics ever. South Korea has mobilized tens of thousands of security personnel, including 50,000 soldiers, to form the most militarized security force in Olympic history.
North Korea agreed at the last minute to attend the Olympics, a diplomatic breakthrough that ruled out the worst-case scenario -- at least temporarily. But when it comes to security deployment, north Korea remains the most unpredictable, with a history of violence when South Korea hosts international sporting events.
On Thursday, a delegation of north Korean athletes arrived in South Korea as part of a large contingent of about 500 athletes, officials and performers. Their arrival brings another set of security challenges, including protecting them from south Korean extremists.
Organizers have long feared that north Korea could test missiles or nuclear weapons during the games, or even set off an escalating chain reaction that could lead to war. Such concerns have eased since the January deal. The two sides agreed to march together under the same flag at the opening ceremony.
But doubts remain about north Korea's intentions.
North Korea will make trouble in one way or another and disrupt the smooth running of the Olympics, said Yoo dong-ryul, director of the Korea Institute of Liberal Democracy in Seoul. "In the years that the Kim dynasty has been in power, north Korea has never had a good cooperation with South Korea."
“朝鲜会以这样或那样的方式制造麻烦，破坏奥运会的顺利进行，”首尔的韩国自由民主研究院(Korea Institute of Liberal Democracy)的院长柳东烈（Yoo Dong-ryul，音）表示。“金氏王朝掌权的这些年，朝鲜从未与韩国有过一次很好的合作。”
In November 1987, 10 months before Seoul hosted the 1988 summer Olympics, north Korean agents detonated a bomb on a south Korean passenger plane, killing all 104 passengers and 11 crew members. One of the agents later admitted to investigators that the aim was to intimidate international athletes and tourists from attending the games.
In 2002, South Korea and Japan co-hosted the World Cup soccer tournament, and a military clash between the two koreas in disputed waters killed six south Korean sailors hours before the south was to play for third place.
However, north Korea does not participate in those sports events. When north Korea participates in south Korean sporting events -- the busan Asian games in 2002 and the incheon Asian games in 2014, for example -- there are no major disruptions.
As a result, south Korean officials and analysts believe the risk of a military provocation, nuclear or not, during the games has been greatly reduced.
But South Korea plans to deploy as many as 60,000 security personnel a day during the games, including 50,000 soldiers, more than double the number deployed during the 2016 summer Olympics in Rio DE janeiro.
The possibility of a missile or nuclear test is very small, said Shin beom-chul, an expert on north Korea at the government-run Korea National Diplomatic Academy in Seoul. "North Korea may use the Olympics as a propaganda opportunity to show that while they may be a nuclear power, they also want peace with their neighbors."
“导弹或核试验的可能性非常小，”首尔由政府开设的国家外交学院(Korea National Diplomatic Academy)朝鲜问题专家申范澈(Shin Beom-chul)说。“朝鲜可能会把奥运会作为一个政治宣传机会，表明尽管他们可能是一个核国家，但他们也希望与邻国和平相处。”
Since north Korea agreed to participate in the games, organizers have scrambled to coordinate security and logistics for the north Korean delegation, which includes a cheering squad.
Jeong se-yun, a senior south Korean police official involved in the preparations, said the north's decision was a relief. "But it also gives us a lot of work," he said. "I've hardly slept in the last month. That's why my eyes are always red now."
参与筹备的韩国道级警方官员郑世延（ Jeong Se-yun，音）说，朝鲜的决定令人大松一口气。“但也给我们增加了大量工作，”他说。“上个月我几乎没睡过觉。这就是为什么我的眼睛现在总是红的。”
One concern is what might happen during the games to prompt north Korean leader Kim Jong Un to recall the athletes and retaliate in some way.
一个担心是奥运会期间可能会发生什么事情，促使朝鲜领导人金正恩(Kim Jong Un)召回运动员，并用某种方式进行报复。
When a north Korean delegation passed through Seoul last month, a small group of right-wing protesters burned a portrait of Mr. Kim. To avoid angering north Korea's representative, who sees Mr. Kim as something close to a god, police quickly put out fires.
North Korea's state media condemned the move as an "ugly crime" committed by "substandard human beings" and warned that South Korea would have only to blame if the north pulled out of the games.
Authorities are also wary of cyber attacks. Either north Korea or Russia is behind the cyber attacks. The Russian delegation was banned from participating in the pyeongchang games under the Russian flag after Revelations of systematic state-sponsored doping.
North Korea has developed a sophisticated hacking capability and has launched a series of damaging attacks around the world, including one in 2013. The attack briefly affected three south Korean Banks and two television stations.
In response to more conventional threats, organizers say security forces plan to deploy both old-fashioned checkpoints and new technologies, such as facial recognition systems, smart cameras and drones. There will also be a tactical surveillance airship hovering in the air.
South Korea is considered one of the safest tourist destinations in the world, with a low crime rate and little record of terrorism outside north Korea. However, the Korea Times reported that immigration authorities said last month that they had deported 17 foreigners believed to pose a terrorist threat. Some of the returnees are said to be from central and southeast Asia.
Overall, we view the games as low-risk, the london-based Risk Advisory Group wrote in a recent analysis of the pyeongchang games. "Compared to the host cities of the 2014 winter Olympics and the 2016 summer Olympics, pyeongchang has a good environment in terms of terrorism, crime and unrest."
“总体上，我们认为本届奥运会风险低，”设在伦敦的风险咨询集团(Risk Advisory Group)在最近对平昌奥运会进行的一项分析中写道。“和距今最近的2014年冬季奥运会和2016年夏季奥运会的主办城市相比，平昌就恐怖主义、犯罪和动荡而言环境良好。”