The 2017–2018 North Korea crisis was a period of heightened tension between North Korea and the United States. The crisis began early in 2017 when North Korea conducted a series of missile and nuclear tests that demonstrated the country's ability to launch ballistic missiles beyond its immediate region, suggesting their nuclear weapons capability was developing at a faster rate than had been assessed by U.S. intelligence. Both countries started exchanging increasingly heated rhetoric, including nuclear threats and personal attacks between the two leaders, which, compounded by a joint U.S.–South Korea military exercise undertaken in August and North Korea's sixth nuclear test in September, raised international tensions in the region and beyond and stoked fears about a possible nuclear conflict between the two nations. In addition, North Korea also threatened Australia twice with nuclear strikes throughout the year for their allegiance with the United States. International relations lecturer and former government strategist Van Jackson said in the book On the Brink: Trump, Kim, and the Threat of Nuclear War that it was the closest the world had come to nuclear war since the Cuban Missile Crisis.
Tensions began to decline in 2018, with North Korea announcing the restoration of the Seoul–Pyongyang hotline and agreeing to hold talks with South Korea about participation in the 2018 Winter Olympics in Pyeongchang. Diplomatic activity flourished during the next few months, with the suspension of nuclear and missile tests by North Korea, and the 2018 inter-Korean summit in late April which culminated in the signing of the Panmunjom Declaration on 27 April 2018. An unprecedented bilateral summit between Kim and Trump was held in Singapore on 12 June 2018. It resulted in a joint declaration calling for the "full denuclearization of the Korean peninsula". A second summit between Kim and Trump took place in Hanoi, Vietnam, on 27–28 February 2019. Though talks there broke down, a third summit took place in the Korean Demilitarized Zone (DMZ) on 30 June 2019, with Trump becoming the first sitting US president to visit North Korea. Follow-up talks later in 2019, however, broke down within hours.
Background
North Korea's nuclear weapons program
In his New Year's Day speech on January 2, 2017, Kim Jong Un, the leader of North Korea, said that the country was in the "last stage" of preparations to test-fire an intercontinental ballistic missile (ICBM).
On May 3, North Korea issued a rare and harshly worded criticism of its chief ally, China, stating that "One must clearly understand that the D.P.R.K.'s line of access to nukes for the existence and development of the country can neither be changed nor shaken[...] And that the D.P.R.K. will never beg for the maintenance of friendship with China, risking its nuclear program which is as precious as its own life, no matter how valuable the friendship is... China should no longer try to test the limits of the D.P.R.K.'s patience[...] China had better ponder over the grave consequences to be entailed by its reckless act of chopping down the pillar of the D.P.R.K.-China relations." The harsh commentary also accused the Chinese media of dancing to the tune of the U.S.
In early August 2017, The Washington Post reported an assessment, made by the U.S. Defense Intelligence Agency in July 2017, which said that North Korea had successfully developed nuclear warheads for missiles capable of reaching the U.S. mainland (a miniaturized nuclear warhead that can fit inside its missiles).
Sanctions on North Korea; trade with China
Since North Korea's first nuclear test in 2006, the UN Security Council had passed a number of resolutions that imposed various sanctions on the DPRK, including restrictions on economic activity. Nevertheless, North Korea's gross domestic product grew by an estimated 3.9 percent in 2016, to about $28.5 billion, the fastest pace in 17 years; the progress was largely attributed to continued trade with China, which accounted for more than 90% of North Korea's international trade.
In late February 2017, following North Korea's February 12 test of the Pukkuksong-2 medium-range ballistic missile, China, which regards its trade with North Korea and the putative missile threat to the U.S. as separate issues, said it would comply with UN Resolution 2321 and halt all coal imports (North Korea's main export) from North Korea. The halt notwithstanding, in April 2017, China said that its trade with North Korea had expanded. In July 2017, China's trade with North Korea, while the ban on North Korean coal was said to have slowed imports from the DPRK, was worth $456 million, up from $426 million in July 2016, the year-to-date trade being up 10.2 percent at $3.01 billion.
In 2017, North Korea was sanctioned several times by the UN Security Council. According to the last set of sanctions of December 22, 2017, oil supplies to the DPRK are prohibited, and all countries have decided to expel North Korean labor migrants within 24 months from the territories of the countries where they work.
China has been opposed to secondary sanctions that may be imposed on Chinese firms that do business with North Korea.
Imprisonment of U.S. citizens
American university student Otto Warmbier was freed from North Korea in June 2017, while in a coma after nearly 18 months of captivity. Warmbier died without regaining consciousness on June 19, 2017, six days after his return to the United States. Some U.S. officials blamed North Korea for his death. In July 2017, U.S. Secretary of State Rex Tillerson authorized a "Geographical Travel Restriction" which banned Americans from entering North Korea.
THAAD in South Korea
Ostensibly to counter North Korea's missile threat, United States Forces Korea (USFK) had been planning deployment of the Terminal High Altitude Area Defense (THAAD) in South Korea, which is designed to detect and destroy intermediate- and medium-range ballistic missiles (not intercontinental ballistic missile). The deployment had faced strong oppositions from China, Russia, and North Korea. In late April 2017, it was reported that while THAAD had originally been scheduled to become operational by the end of 2017, this could occur sooner. According to U.S. Forces Korea's announcement, THAAD stationed in South Korea had reached initial operating capability (IOC) on May 1, 2017.
Timeline
USS Carl Vinson's movements: April 2017
Following North Korea's test-firing of a medium-range ballistic missile from its eastern port of Sinpo into the Sea of Japan on April 5, which came a month after four ballistic missiles were fired towards the Sea of Japan, tensions increased as U.S. president Donald Trump had said the U.S. was prepared to act alone to deal with the nuclear threat from North Korea. On April 9, the U.S. Navy announced it was sending a navy strike group headed by the supercarrier USS Carl Vinson to the West Pacific ("to sail north and report on station in the Western Pacific Ocean after departing Singapore April 8"), but due to apparent miscommunication inside the U.S. administration, the naval move was presented as one towards the Korean peninsula. This information was backtracked by the U.S. government a few days later.
The April 9 announcement by the Navy led to a "glitch-ridden sequence of events". On April 17, North Korea's deputy United Nations ambassador accused the United States of turning the Korean peninsula into "the world's biggest hotspot" and the North Korean government stated "its readiness to declare war on the United States if North Korean forces were to be attacked." In reality on April 18, Carl Vinson and its escorts were 5,600 kilometres (3,500 mi) from Korea engaged in scheduled joint Royal Australian Navy exercises in the Indian Ocean. On April 24 the Japanese destroyers Ashigara and Samidare participated with Carl Vinson in tactical training drills near the Philippines; North Korea threatened to sink her with a single strike. Carl Vinson had been in the South China Sea in 2015 and again in February 2017 on routine patrols. In late April 2017, Trump stated that "[t]here is a chance that we [the United States] could end up having a major, major conflict with North Korea".
On April 24, North Korea marked the 85th anniversary of the Korean People's Army by what was said to be "its largest ever military drill," conducted in Wonsan. The following day, it was reported that the United States and South Korea had begun installing key elements of the THAAD missile defense in South Korea's Seongju County.
ICBM test-flight on 4 July
On July 4 North Korea conducted the first publicly announced flight test of its ICBM Hwasong-14, timed to coincide with the U.S. Independence Day celebrations. This flight had a claimed range of 933 kilometres (580 miles) eastwards into the Sea of Japan (East Sea of Korea) and reached an altitude of 2,802 kilometres (9,193,000 ft) during a 39-minute flight. The U.S. government experts classified the missile launch as a big step in Pyongyang's quest to acquire a nuclear-tipped weapon capable of hitting the U.S. North Korea declared it was now "a full-fledged nuclear power that has been possessed of the most powerful inter-continental ballistic rocket capable of hitting any part of the world".
USFK said in a statement dated July 4, 2017: "Eighth U.S. Army and Republic of Korea (ROK) military personnel conducted a combined event exercising assets countering North Korea's destabilizing and unlawful actions on July 4." South Korea's Hyunmoo-2B and U.S. Army Tactical Missile System missiles were launched during the drill.
Rhetorical escalation in August 2017
On August 8, 2017, President Donald Trump warned that North Korean nuclear threats would "be met with fire, fury and frankly power, the likes of which the world has never seen before," after the mass media reported that a US intelligence assessment had found that the country had successfully produced a miniaturised nuclear warhead capable of fitting inside its missiles. According to New York Times correspondent Michael S. Schmidt, Trump proposed using a nuclear weapon against North Korea and blaming the attack on another country, but was dissuaded by John F. Kelly. President Trump also remarked of North Korea's leader Kim Jong Un: "He has been very threatening beyond a normal state." Within hours, North Korea responded by announcing that it was considering attacking U.S. military bases in the US territory of Guam.
On August 10, 2017, North Korean Lt. Gen. Kim Rak-gyom responded to Trump's speech of "fire and fury," saying his words were "nonsense" and asserting that "reasonable dialogue" wasn't possible with Trump as president of the US. The North Korean governmental news agency KCNA reported that Kim Jong Un's military was considering a plan to fire four ICBMs, type Hwasong-12, into the Philippine Sea just 30–40 kilometers away from the island Guam. The flight time of missiles was estimated to be exactly 17 minutes and 45 seconds. A report by the KCNA suggested the plan would be put into operation in mid-August. U.S. officials stated that Joseph Y. Yun, the US envoy for North Korea policy, and Pak Song-il, a senior North Korean diplomat at the country's UN mission, were making regular contact during this dispute, through a conduit of communication they called the New York channel.
On August 11, Trump wrote on Twitter: "Military solutions are now fully in place,[ ]locked and loaded,[ ]should North Korea act unwisely. Hopefully Kim Jong Un will find another path!" Former U.S. Ambassador to the United Nations John Bolton and former U.S. Secretary of Defense Leon Panetta stated that the standoff between the U.S. and North Korea over Pyongyang's nuclear weapons program was comparable to the Cuban Missile Crisis.
Bob Woodward, in his 2020 book Rage, quoted Mike Pompeo as saying the national security team "never knew whether it was real, or whether it was a bluff", and reported that Jim Mattis slept fully dressed due to concerns about a North Korean attack.
On August 14, Ukraine's Chairman of the National Security and Defense Council, Oleksandr Turchynov denied that it had ever supplied defense technology to North Korea, responding to an article in the New York Times that said North Korea might have purchased rocket engines from Ukrainian factory Yuzhmash, who have also denied the report.
On August 15, the North Korean leader said he was delaying a decision on firing missiles towards the US Pacific territory of Guam while he waits to see what Trump does next.
From August 21–31, the U.S. and South Korea conducted the 2017 Ulchi-Freedom Guardian exercise that was billed by U.S. Forces Korea as slightly smaller than the previous year's, with 17,500 U.S. troops participating; an editorial carried by North Korea's official Rodong Sinmun newspaper condemned the drills as "the most explicit expression of hostility against us."
On August 25, North Korea fired three missiles from Kangwon Province in the southeastern part of the country. According to Cmdr. Dave Benham of US Pacific Command, one of the missiles exploded on launch while the other two suffered critical failures in flight, splashing down in the Sea of Japan after flying a distance of 250 kilometers (160 mi).