Since the beginning of the North Korean nuclear issue， it has become an important factor affecting the peace and stability of the Korean Peninsula. In recent years， the issue has become a matter of global concern because of the failure to achieve any resolution and the subsequent deterioration of the problem. The initial momentum achieved by the Six-Party Talks has ground to a halt for nearly a decade， demonstrating that while the principles of the Six-Party Talks for the denuclearization of the Peninsula and for regional peace and stability are recognized to varying degrees by all the parties， the differences are significant， particularly with regard to conditions for restarting the talks. Perceptions of other parties’ intentions are prevalently negative and basis for mutual trust is seriously lacking. The past year 2016 witnessed the chaotic and turbulent situation on the Korean Peninsula， and the issue of denuclearization was brought to a crucial juncture， which more clearly exposed the structural conflicts behind the problem， namely， the maneuvering among neighboring great powers and the test of wills between the two Koreas. The decision to deploy THAAD （Terminal High Altitude Area Defense） by the South underlined the negative development and interaction of these sets of contradictions， making the nuclear-free dilemma more complicated. Under the new circumstances， it is necessary to reexamine the denuclearization issue of the Peninsula， profoundly recognize the root of the problem， face up squarely to the deep-lying contradictions， and create conditions for solving fundamental issues， so as to promote pragmatic cooperation toward the realization of a stable and secure peninsula.
　　Deteriorating Situation on the Korean Peninsula Creating Further Obstacles
　　Looking at the background of the nuclear issue， we can see that the terrain of the Korean Peninsula has undergone enormous changes over the last two decades. The deep shocks in 2016 have in many respects shaken the will to cooperate toward problem resolution and have created new obstacles.
　　Serious situation of North Korean nuclear and missile tests
　　Since the first nuclear test in October 2006， North Korea’s first three nuclear tests have been conducted at an interval of around three or four years， but in 2016， North Korea conducted two nuclear tests in January and September respectively. More shocking for the world was the fact that North Korea after the fourth test announced that they had tested a hydrogen bomb； and after the fifth test， the DPRK announced， in the new form of a statement by the North Korea Weapons Research Institute， that the test was intended to appraise the strength of the nuclear warhead. Although there is widespread suspicion of North Korea’s self-proclaimed success， there is little doubt that the DPRK nuclear weapons technological development in 2016 has moved closer to what is a bottom line for the United States and South Korea. The DPRK’s statement was meant to declare its intention to improve its nuclear capabilities and the strength of its nuclear warheads. 　　In addition， the number of missiles fired by North Korea in 2016 is far more than in the past， particularly with regard to submarine-launched missile tests. On June 22， North Korea conducted two missile tests with the second one flying 400 km before plunging into the Sea of Japan， which is considered the maximum reach of the Musudan missile. And it was successful. Analysis pointed out that North Korea hoped to thereby highlight its ability to launch a surprise attack and avoid interceptions， and to show its breakthroughs in missile range. It is noteworthy that， after the fourth and fifth nuclear tests which further enhanced its nuclear capabilities， the DPRK increased the throw-weight of its missiles. In his 2017 New Year’s message， North Korean leader Kim Jong-un said the DPRK’s development of intercontinental ballistic missiles had entered its final stages. South Korean media， quoting the information from ROK and US military and diplomatic circles， claimed that North Korea had created two new ballistic missiles， assuming that these were the missiles Kim Jong-un referred to in his New Year’s message and might be launched earlier than expected. On February 12， 2017， North Korea， after a few months of silence， launched a Pukguksong-2 medium-range missile. South Korea said the missile flew more than 500 kilometers before falling into the Sea of Japan. It was analyzed that the success of the test， although not of an intercontinental missile as people had feared， should be seen as another indication of North Korea’s determination to push fully toward developing an intercontinental ballistic missile.
　　In addition to accelerating the nuclear weapons technology， the DPRK’s determination to become a nuclear power has been expressed in a much starker and more bombastic manner. Subsequent to its formal inscription of the program into its constitution in 2012 and declaration in 2013 that the development of the North Korean economy went hand in hand with its development of nuclear weapons， at the 7th Congress of the Workers’ Party of Korea in May 2016， Kim Jong-un made a speech in which he said that the development of nuclear weapons would represent a permanent strategic thrust and an unshakeable commitment of the DPRK. At the same time， in order to legitimize and regularize the DPRK’s status as a “nuclear power，” he also proposed “to develop DPRK foreign relations in accordance with its status as a nuclear power.”
　　In short， the DPRK nuclear program has made technological breakthroughs and has become more assertive in its nuclear strategic intent. The nuclear situation is reaching a critical juncture， and possibility of unpredictable conflicts between the parties involved is on the increase. 　　North-South conflict turning unprecedentedly acute
　　The relationship between the two Koreas is the key element in the evolution of situation on the peninsula. The armistice following the Korean War has kept peace for over half a century despite occasional disturbances. The primary reason is that both governments had to different degrees maintained an aspiration for cooperation and offered necessary acknowledgement of the other party’s rights and privileges as a state， which converged to prevent a conflict. But for over a year， confrontations between the Park Geun-hye and Kim Jong-un governments have provided shocks to the abovementioned bottom line， leading to significant deterioration in their relationship and upsetting the multiple safety measures which were in place to prevent conflicts. The situation on the peninsula is turning unprecedentedly dangerous.
　　The antagonism is first expressed in the suspension of economic relations. In the happier times of North-South cooperation， there were three trademark projects： Mount Kumgang tourism， arranged reunions between separated family members， and the Kaesong Industrial Complex. The relations between the two sides cooled during Lee Myung-bak’s administration. The Mount Kumgang tourism was suspended on the ground that a South Korean tourist was shot by the North， the family reunions were occasionally interrupted， while the Kaesong Industrial Complex was barely in operation despite constant possibility of shutting down. According to the 2016 White Paper issued by the Ministry of Unification of ROK， the production volume of Kaesong Industrial Complex reached $563.29 million in 2015， for the first time breaking the annual record of $500 million. The cumulative production volume of the Complex from 2005 to 2015 was $3.23 billion. In 2016， however， no improvement was witnessed in Mount Kumgang tourism， separated family reunions went unmentioned， and Kaesong Industrial Complex， the only cooperation project remaining from the Kim Dae-jung era， finally came to an end. After the fourth nuclear test， then President Park Geun-hye ordered the Kaesong Industrial Complex to shut down. The Ministry of Unification issued a toughly worded Government Statement regarding the Complete Shutdown of the Gaeseong Industrial Complex and started to withdraw 124 South Korean companies and 184 South Korean nationals. On March 10， 2016， the DPRK declared all economic cooperation agreements invalid effective immediately， and because of South Korea’s unilateral decision to close Kaesong， it would liquidate the assets of all South Korean companies and institutions within its border. The South Korean newspaper JoongAng Ilbo commented that the last bond between the South and the North also disappeared with the cessation of Kaesong； the trust building process through communication had come to an end and the notion of inducing changes in the North by way of Kaesong Industrial Complex had also lost ground. 　　The confrontation is also expressed in the steady deterioration in their political and diplomatic relations. Despite decades of separation， both sides have never given up the objective of unification of the two Koreas in their respective own favor， and both regarded the other as unrecovered territory. But in the context of international relations， with both member states of the UN， the two countries had been restrained and cautious in their dealings with each other. Moreover， since previously both countries had to a certain degree the intention to improve relations and exert change on the other party， for a long time both sides were in agreement with the consensus reached in the 1970s， seeking peaceful reunification in the form of a federated state or confederation. But due to the deteriorating bilateral relationship in 2016， they began to raise issues which had previously been considered taboo. South Korea announced publicly that it wished to achieve unification with liberal democracy in accordance with the ROK constitution， namely unification into one single system. In a public speech， then President Park Geun-hye even appealed to North Korean nationals to at all times seek refuge and freedom in the South. To further isolate the North， South Korean high ranking officials， in their international meetings and visits， have taken opportunities to incite defections in the countries that maintained good relations with North Korea. In this way， for instance， in 2016 South Korean officials on official visits successfully persuaded Uganda， Poland and some other countries to sever military ties with the North. These efforts on the part of the South no doubt exacerbated North Korea’s hostility toward the South and also narrowed the space for the two to conduct negotiations.
　　In addition， military confrontation is also approaching a dangerous point. In response to North Korea’s two nuclear tests in a single year and a number of missile test firings， South Korea and the US have raised the frequency and level of their joint military drills and deployment. In addition to increasing the scale and intensity of their annual joint military exercises like Key Resolve， Foal Eagle and Ulchi-Freedom Guardian， some extra drills like anti-submarine exercises， early warning exercises， air-ground combat exercises and artillery firing were also conducted. And what attracted particular attention， after the DPRK’s fifth nuclear test， was South Korean military’s formal announcement of a Massive Punishment and Retaliation plan （KMPR） with North Korean supreme leader Kim Jong-un as the chief target. According to South Korean media， among the plans of large-scale attacks on the table， air strikes ranked first. In the event of an emergency， the South Korean military planned to use Hyunmoo-3 cruise missiles and Taurus air-to-surface missiles to flatten the area dozens of kilometers around Kim Jong-un’s office in Pyongyang， his private plane and trains. The South Korean military openly stated that were the supreme leader and top leadership of the DPRK military eliminated， the government of North Korea would be totally paralyzed and the threat to South Korea would disappear. But North Korea didn’t flinch in the face of the South’s intimidation. It imported multiple types of radar systems to detect the entry of stealth fighter jets like the F-35. It also strengthened the air defense network around Pyongyang and deployed air defense missiles with different ranges and calibers. At the same time， North Korea clearly stated that if the slightest trace of movement by the South Korean forces were detected， North Korea would immediately initiate combat measures and that the first target would be the Blue House and the second target would be US military bases in the Asia Pacific and the US territory. The recently conducted US-ROK joint military exercise 2017 was the largest in history and involved US strategic strike weapons. The US and South Korea will also conduct exercises for wartime troop reinforcement， pre-emptive strikes， elimination of North Korean command headquarters， and missile interception using THAAD. It’s obvious that with the intensification of military deployment and action plans by the two Koreas， the possibility of conflict or even all-out war is increasing. 　　South Korea’s political shocks hindering dialogue process
　　South Korea’s political turmoil is the most sudden and dramatic event in the recent evolution of the Peninsula’s situation. On October 24， 2016， the South Korean television station JTBC revealed in breaking news that President Park Geun-hye had been manipulated by her female close friend Choe Sun-sil. Choe was not only suspected of accessing confidential documents， but also of interfering with the personnel appointments at the Blue House. She was said to have even used her relationship with Park Geun-hye to make South Korea’s consortiums donate to Mir Foundation and K-Sports Foundation which were under her control. She also used her influence to enroll her daughter in the famous Ewha Womans University. The news provoked a major public clamor. South Korean people took to the streets to hold candlelight demonstrations， urging Park Geun-hye to step down. Under the pressure of public opinion， Park Geun-hye expressed her apology in a national speech.
　　However， the issue didn’t stop but continued to unravel and showed that people’s resentment and indignation toward the Park Geun-hye administration went far beyond this single instance of “favoritism.” Age-old abuses in South Korean politics had reached a point at which internal and external national policies were affected and the political landscape was shocked. On December 3， 2016， National Assembly members from the opposition parties and those without party alignment introduced a joint impeachment motion against President Park Geun-hye to the Assembly on the grounds that Park had allowed her close friends to interfere with state affairs， that her government had failed to save lives when the passenger liner Sewol sank， and that she was suspected of taking bribes in relation to Choe Sun-sil’s coercion of big companies into giving donations. On December 9， 299 of the 300 members of the National Assembly voted on the motion. The result was 234 yeas， 56 nays， 2 abstentions and 7 invalid votes and the impeachment motion was passed. The voting result showed that on the issue of impeachment， there was an overwhelming majority in the Assembly. Even if all the 172 congress members from opposition parties and those with no party affiliation voted in favor of the motion， there were more Assembly members within the ruling party who voted yes than those who voted no. Beginning on December 10， Park Geun-hye’s role as president was suspended. In the meantime， the Korean people continued to take to the streets in protest and Park’s approval rating kept falling. In the beginning， Park Geun-hye only admitted the mistake of believing her close friend but denied that she had violated the Constitution. While Park used various pretexts for refusing to attend an impeachment hearing， her supporters accelerated the pace of the controversial deployment of THAAD and obstructed investigation of Park based on the special prosecution system. After Park Geun-hye’s numerous refusals to attend inquiries and court trials in person and acting president Hwang Kyo-ahn’s refusal to extend the time for investigation beyond February 28， 2017， the Special Prosecution Team announced the conclusion of their investigation and determined that Park was under suspicion of corruption. On March 10， the Constitutional Court of Korea ruled to uphold the impeachment with an unanimous 8 votes from all the judges. Park Geun-hye became the first president in South Korea to be stripped of power through impeachment， and the election of the next president will be conducted within 60 days. 　　The South Korean people have a tradition of demonstrations and there is precedent of political reforms driven by street politics. For example， on April 19， 1960， about a hundred people， largely young students， were killed in protests against political corruption， but the protest led to the ending of authoritarianism and the resignation of President Syngman Rhee. Another example is the June Struggle of 1987， which called for democracy and constitutional amendment. It gave birth to South Korea’s democratic constitution characterized by direct election of the president. Protests after 1987 have mostly been peaceful and aimed at specific targets， the most typical being the candlelight demonstration against the import of American beef in 2008. The nationwide demonstration demanding that President Park step down is quite different from previous ones and has broken many records in South Korean politics. Many things are unprecedented such as the number of protesters， the duration of the protest， the low support rating of the president and the huge division within the conservative party. At the moment， there has been intense competition for candidacy in the next presidential election within different political parties. The partisan division and the competition between progressive and conservative blocs reflected in this event will continue on into the election season.
　　Although there are still many possible outcomes in South Korean politics， one thing is certain. The instability of South Korean politics that was reflected in Park Geun-hye’s scandal is more broadly a reaction against the abuses of the political system； it also stems from the resentment over the sufferings imposed on ordinary people by the sluggish economy of the last few years， coupled with the wrangling of different groups over foreign policies which has directly affected social stability and economic development. Looking at the situation with regard to the nuclear issue， President Park’s foreign policy during the last two years has been exceedingly and increasingly narrow-minded， contributing to favoritism and provoking domestic ferment. Before the revelation of her relationship with Choe Sun-sil， President Park had made a series of decisions that deviated considerably from public opinion， including her abuse of public power to suppress opposition parties， for which she was heavily castigated. It is highly likely that her firm refusal to accept North Korea’s appeal for talks， her deployment of THAAD， and her signing an agreement with Japan on the sensitive issue of comfort women and intelligence sharing， were done to divert people’s attention from her troubles and to ease the public pressure on her. After the revelations and impeachment， she stepped up efforts to deploy THAAD， criticized North Korea more intensively， and instigated a split in the public with regard to the North Korea policy. These efforts by Park Geun-hye were aimed to vindicate herself from responsibility in the corruption case. In short， the political turmoil in South Korea may have only just begun. Domestic issues will perhaps continue to reverberate and affect the course of the nation， and the implications on the foreign policy， which has already been distorted by these events， are almost inevitable. 　　THAAD Deployment Revealing Complicated Political Jockeying
　　The successive shocks on the peninsula is fundamentally the explosion of deep-rooted conflicts among different parties， while the waves created by the THAAD deployment reflect the complicated influence on the region of the discords between the countries involved.
　　The deployment of THAAD has been a long conceived plan by the US to weaken China’s military strength and establish a global anti-missile system. The plan had not materialized because of China and Russia’s objection. After North Korea’s fourth nuclear test， military circles and conservative forces within the US and South Korea used the nuclear threat from the DPRK as a pretext to again raise the issue of THAAD deployment. In response， Chinese Foreign Minister Wang Yi said that China was gravely concerned over the tendency of the US to deploy THAAD in South Korea. The surveillance radius is more than necessary for the defense of the Korean peninsula， and will not only directly hurt China’s strategic security， but also the interests of other neighboring countries. China is firmly opposed to the harm to its legitimate interests by any country which uses the North Korean nuclear issue as an excuse. In the face of China’s firm statement， then Secretary of State John Kerry argued that the US had no definite plans for the deployment of THAAD and that the US was consulting with other countries about its deployment and no final decision had been made. South Korea had also officially made a statement， saying it hadn’t received any request from the US， and that it was not in contact with the US about the issue and no final decision had been made.
　　But on July 8， several months after that statement was made and as cooperation became urgent in order to respond to North Korea’s Musudan missile launch， and simultaneously with the final award on the China-Philippines South China Sea arbitration case pending to be released， the US and South Korea issued a joint statement announcing the decision to deploy THAAD in the US base in South Korea. China， Russia and North Korea immediately expressed their opposition. And the news also stirred up a strong reaction among the Chinese people and was condemned in the media. This decision also revealed the extreme vulnerability of cooperation between China and South Korea. In South Korea， news of the deployment also triggered many protests and some people from political and academic circles wrote to criticize the imprudence and lack of insight in the decision to deploy THAAD. 　　Even so， South Korea’s military and conservative forces continued to push forward the depoyment of THAAD even after the suspension of President Park. The Ministry of National Defense of South Korea said that the military was stepping up efforts to deploy THAAD and that if all went well， the system would be deployed as early as May 2017. According to the analysis of South Korean media， the effort to accelerate the deployment ahead of schedule perhaps reflected the intention of the military authorities to avoid the uncertainties created by the impeachment of President Park. It was also a statement to the outside world that the deployment of THAAD would not be affected by political changes. On February 2， 2017， the new US Secretary of Defense James Mattis visited South Korea after assuming office and underscored that the deployment of THAAD would proceed as scheduled. On February 28， South Korea’s Ministry of National Defense announced that it had reached an agreement on land swap with Lotte to deploy THAAD. This showed that the deployment of THAAD was put on a fast track and will soon begin construction.
　　Although China expressed its strong opposition and with the protest movements in South Korea also gaining in strength， the THAAD deployment hasn’t yet been finally settled， the issue has clearly revealed the deep divisions between the parties.
　　First， behind the deployment of THAAD in South Korea lies the struggle of wills in Northeast Asia between the major powers， and this structural contradiction has become increasingly clear and vocal with China’s rise. By deploying THAAD in South Korea， the US improves its comprehensive and effective missile defense system， undermines China and Russia’s nuclear deterrence and broadens the trilateral cooperation between the US， Japan and South Korea. China and Russia will never allow the deployment of an antimissile system in such a forward position， and will also have to guard against the US attempt to encircle and contain them by way of THAAD. The deployment， disguised aiming at North Korea， resembles similar occasions in recent years when the US and Japan have consolidated their regional strategic layout using the North Korean threat as a pretext. The fundamental driving force of the actions is to respond to China’s rapid rise. Ignoring the protests from China and Russia to move forward with THAAD reveals the intensifying political contest between the major powers on the peninsula.
　　Second， the hype around THAAD in South Korea is also a reflection of the increasing confrontation with North Korea. The contest between the two Koreas is the other contradiction on the peninsula， and the growing imbalance and increasing differences in strength between the two sides make it a dangerous relationship as neither side has relinquished the determination to unify the peninsula. Overwhelmed by fear of being absorbed by the South， the North has become even more determined to develop its nuclear capability. Meanwhile， the failure to convince the North to give up its nuclear ambitions has created great anxiety in the South and triggered a greater desire to unify the peninsula by using its absolute advantages. In this context， the THAAD deployment has shown that the Park Geun-hye government was aware of its inability to make progress with North Korea. It also reveals that the South Korean conservative forces no longer have any scruples in moving forward with their strategic objectives which could entail serious consequences， and that they have no hesitation in reaching those goals even at the cost of peace. 　　And finally， the THAAD crisis has created a conflict of interests among parties， underlining the negative interactions between the abovementioned two structural contradictions. The THAAD deployment is not only impinging on China’s security space but is also damaging China’s diplomatic relations with South and North Korea. On November 28， 2016， as the issue of THAAD was roiling the Korean Peninsula， Japan was reported to have set up a special agency to formally discuss the introduction of THAAD， taking advantage of this opportunity to push forward military cooperation between the US， Japan and South Korea， which was clearly directed against China. Park Geun-hye abandoned her diplomatic theory of finding balance between China and the US and bound herself up completely with the US on the hope that the US could promise the protection of South Korea and mount more pressures on the North. There is no doubt that North Korea will regard the confrontation between China， on the one hand， and the US and South Korea， on the other， as an opportunity to develop itself and will not give up efforts to push forward its strategic objectives.
　　North Korean Nuclear Issue Reaching a Critical Juncture
　　The profound shocks on the Korean Peninsula have cast a shadow on the possibility of a future denuclearization of the region and have pushed all sides to a point where there is little room for maneuver.
　　From the perspective of the relationship between the two Koreas， continuing along the current path will wreck the traditional mechanisms for safeguarding peace. North Korea needs to conduct more nuclear and missile tests in order to demonstrate its determination and intimidate the South， and with these actions by North Korea， it is only a matter of time before they reach a level that represents the bottom line of the US and South Korea. The South has almost completely given up on the possibility of negotiations in its dual track of combining pressures and negotiations. Pursuing a policy of only pressuring the DPRK， it would be hard to avoid escalation into conflict. Relying on the major powers to prevent an out-of-control situation on the Peninsula， or thinking that the major powers can rein in the adventurous acts of both the North and the South， are probably already vain hopes.
　　The change of administrations in the United States has also created uncertainties in the US-ROK relationship. Although in his election campaign， Donald Trump said he would communicate with Kim Jong-un， and seek to resolve their differences， with Trump now in office the nuclear threat becomes real and the Trump administration will list the issue as the top priority on its Asia Pacific agenda. The administration will no longer proceed with a policy of “strategic patience” toward North Korea. There is a possibility of talks with North Korea， but the US will not budge from its position of denying the DPRK of its pursuit for nuclear power status and a bilateral resolution to achieve denuclearization is highly unlikely. At the same time， the US will not sit by to watch China play a leading role in resolving the crisis other than by the US playbook. Therefore， the possibility of tougher positions following failed talks between the US and North Korea is more likely than an easing of relations through negotiations. There is a greater possibility that progressive forces may take power in South Korea in 2017. Even so， South Korea faces several challenges in order to adjust its policies. The unprecedented deterioration in the relationship between North and South Korea has already profoundly affected the politics， academia and even public opinion. The deployment of THAAD is already in progress and South Korea will face a difficult choice in its relations with China and the US； even a decisive choice of one over the other will still make it difficult to realize its goals. The impeachment of President Park Geun-hye and its consequences will usher in a new round of criticism over the age-old abuses of political power. The confusion in the power relationship and the operation of domestic policies will not come to an end immediately and this will limit any readjustments in foreign policy. 　　What’s more noteworthy， the shocks on the Korean peninsula， on one hand， have revealed the deep conflicts of interests among the countries and， on the other hand， have changed the pattern of relationship between all the parties involved oriented toward the North Korean nuclear issue. Not only can the nuclear threat sufficiently explain the contradiction between South and North Korea， the differences and discord between China， the US， Japan and South Korea cannot simply be explained by their different approaches to the North Korean nuclear issue. The issue of THAAD deployment magnifies and lays bare the strategic conflict of interests between China and Russia on the one hand， and the US， Japan and South Korea on the other， which will affect the cooperation in moving forward on denuclearization and is of no use in preserving regional peace and stability and may even push the Peninsula again into a Cold War quagmire.
　　However， there are still favorable factors which may save the situation. China’s policies toward the Korean Peninsula have become more active， clear and balanced. After the fourth nuclear test by North Korea， China formally put forward a proposal which would create the progress of denuclearization in parallel with transition from armistice to peace. To be specific， this would combine the wish of the international community for a denuclearized Korean Peninsula with the rational concerns of North Korea： concurrent negotiations on denuclearization and transition to peace in a staged manner toward a comprehensive resolution of differences. On March 8， 2017， Chinese Foreign Minister Wang Yi further elaborated on the policy and called it “double suspension，” that is， North Korea would suspend its nuclear and missile activities in exchange for the suspension of large-scale US-South Korea military exercises and all sides would return to the negotiating table. Previously in the process of dealing with the North Korean nuclear issue， China’s role was mainly to facilitate peace negotiations， and even when chairing the Six-Party Talks， the main task of China was to serve as a go-between of the parties. Now China becomes more active and its position and appeal more clear. Its support for the denuclearization of the Korean Peninsula is unambiguous and its implementation of the UN sanctions absolute， but it also underscores that talks and negotiation are the fundamental ways to solve these problems and it will not sit by and watch actions that destabilize the region and hurt China’s interests. Although at the moment China’s proposals haven’t received active response from the countries comprising the Six-Party Talks， it will in time gain the understanding and support of all the parties since it covers each party’s concerns and would secure peace and security of the Peninsula for a long time.
　　The actions of North Korea are carrying a heavy price， suffering the severest sanctions in history. During the time of the US and South Korean elections， North Korea adopted a wait-and-see stance. In response to the largest scale joint military exercise by the US and South Korea， North Korea launched missiles， but with some restraint. Affected by the incident of a North Korean citizen killed in Malaysia， the Trump administration’s first attempt to contact North Korea did not succeed. North Korea won’t give up its efforts at this point. Furthermore， the shocks of the past year have put everybody on alert. If all the parties are able to remain calm under these critical circumstances and try to adjust their policies in practice， they can obviously become an important positive factor for restarting the dialogue on denuclearization.