SEOUL (Reuters) - South Korea’s Unification Ministry, responsible for inter-Korean affairs, has seen its standing wax and wane along with relations between the still officially warring neighbors.

The ministry returned to prominence this year after three summits between South Korean President Moon Jae-in and North Korean leader Kim Jong Un ended with pledges to defuse military tensions, restart economic cooperation and formally end the 1950-53 Korean War.

But those efforts have placed the ministry in a bind, with Washington wary of rapid progress between the two Koreas that may undermine international sanctions and efforts to dismantle the North’s nuclear and missile programs.

Here is a summary of the ministry’s history, mission and how its work has evolved in line with changes in domestic political tides and diplomatic dynamics.

ONE OF A KIND

The South’s full-fledged Unification Ministry is the only one of its kind in the world, with its northern counterpart being the Committee for the Peaceful Reunification of the Country.

Amid fears Pyongyang might forcibly reunify the peninsula, former military dictator Park Chung-hee created the ministry’s 45-strong precursor in 1969, at the height of the Cold War, as a public propaganda body against the North.

Research papers issued by the agency in 1969 included “Communist forces and their strategy in Far East,” “The North Korean puppet regime’s Japan policy” and “Communist China’s Asia policy and Korea reunification,” the National Archives of Korea show.

An educational video distributed by the agency in 1972 explores how to utilize North Korean defectors in the South and pro-Pyongyang Korean residents in Japan for “psychological warfare” against the North.

“For the Park regime, unification was a good excuse to heighten wariness against the North and justify its military rule,” said Chung Se-hyun, who joined the ministry in 1977 and served as minister from 2002 to 2004.

HEYDAY AND DECLINE

As relations thawed in the early 1970s, the unification agency’s role evolved to include cross-border dialogue and exchanges.

The ministry expanded its duties in the 1990s, studying human rights abuses in North Korea and helping resettle defectors who fled amid a devastating famine in the mid-1990s.

The ministry’s heyday came under liberal presidents Kim Dae-jung, who upgraded its status to full-fledged ministry in 1998, and his successor Roh Moo-hyun.

It played a pivotal role when Kim and Roh met with North Korea’s late leader Kim Jong Il, for summits in 2000 and 2007 respectively, in Pyongyang. Staffing grew to 550 by 2007.

But a series of incidents and attacks and the North’s pursuit of nuclear-armed missiles, followed by international sanctions and the halt of joint economic projects, saw the ministry’s influence wane.

In 2008, newly elected conservative president Lee Myung-bak cut staff by 15 percent. In 2016, his conservative successor Park Geun-hye, shut down the Kaesong joint industrial park in the North, the last remaining symbol of inter-Korean rapprochement.

NEW WIND AND DILEMMA

Moon, a former chief of staff to Roh and who prepared him for the 2007 inter-Korean summit, took office in May 2017 vowing to restore dialogue.

Moon wants to build an inter-Korean economic community, under a multibillion-dollar “New Korean Peninsula Economic Map”. It envisions joint industrial zones and transportation links, including by reopening the Kaesong factory park and resuming tours to the North’s Mount Kumkang resort.

Moon’s reconciliation policy has given a renewed sense of purpose to the 560-strong ministry, but at the same time posed a dilemma over how to proceed with inter-Korean initiatives while advancing nuclear talks between Pyongyang and Washington.

Kim Jong Un vowed to work toward denuclearization in his June summit with U.S. President Donald Trump, but the two countries have since failed to agree on a specific timeline or concrete steps to reach that goal in their subsequent negotiations.