A year ago Thursday, North Korea test-fired the Hwasong-15 intercontinental ballistic missile, claiming its success completed the country’s endeavors to become a “nuclear state.” Its young dictator, the North boasted, had acquired the capabilities to hit targets as far as the US mainland with a nuclear-tipped missile. The world was put on alert.

In a little more than a month, however, Kim Jong-un offered an olive branch to South Korea and the international community. North Korean athletes participated in the PyeongChang Winter Olympics in February, paving the way for exchanges of senior government officials between the two Koreas.

Ultimately, President Moon Jae-in met Kim on three occasions, most recently in Pyongyang in September. Inter-Korean peace and reconciliation programs have been flourishing under agreements made during those three rounds of top-level talks.

Hopes for the disarmament of North Korea and permanent peace on the Korean Peninsula ran even higher when US President Donald Trump and Kim held a historic summit in Singapore in June.

But despite repeated commitments and high-level follow-up talks between the two sides, the denuclearization talks were deadlocked. The US and North Korea remain at odds over who should take the next step.

Basically, the US demands that Pyongyang take substantial denuclearization steps, such as declaring all its nuclear-related materials and facilities and accepting outside inspections, while the North is pressing Washington to relieve sanctions and guarantee its security in return for actions it has already taken. These include a moratorium on new tests and the destruction of some of its nuclear facilities and missile bases.

The Seoul government has tried to mediate between the two sides, but the latest developments show just how difficult and intricate this intermediary role is, especially regarding the harshest-ever sanctions placed on the Kim regime.

Last week, the Seoul government was granted a sanctions exemption from the UN to conduct a joint survey in the hope of ultimately reconnecting cross-border railways with the North. The survey requires the South to take fuel oil, a key blacklisted item, and other materials into the North. The United Nations Command had previously turned down a similar request from South Korea.

The UNC action foiled the Moon government’s hopes of conducting the joint survey at an early date and hampered the progress of the railway and road reconnection projects. Seoul officials say that breaking ground for the construction work can still take place before the end of this year, but the delay demonstrated differences between South Korea and the US over the legitimacy of relieving sanctions without any notable progress on denuclearization.

Of course, improved relations between the two Koreas would facilitate denuclearization talks between the US and the North. But clearance for the joint survey alone should not be seen as a major shift on the part of the US government or the international community.

Most importantly, the exemption applies only to the joint survey. The Seoul government needs to obtain additional authorization for the road and railway connection work.

In addition, the North, while using the inter-Korean transportation project as a means to tear holes in the sanctions, is not likely to change its position: that inter-Korean relations have nothing to do with denuclearization talks with the US.

A fundamental problem is that the US is not willing to make any considerable concessions before the North takes substantive action on disarmament.

In fact, the Trump administration has imposed additional sanctions on the North even since the Singapore summit in June. Last week’s New York Times report that US prosecutors were investigating Japan’s largest bank over an alleged failure to prevent money laundering in connection with North Korea is yet another example of Washington’s unflagging determination to leave the sanctions in place for now.

This should stand as a valuable lesson for the South Korean government, as well as its banks and companies, to take care not to breach international sanctions against the North. Most importantly, the government should not be impatient to improve relations with the North. Instead, it should maintain a pace for the reconciliation efforts that is in tandem with the progress of denuclearization. A real breakthrough, of course, can happen only if the North changes its stance.