SEOUL -- Just over two years since the leaders of the two Koreas shook hands over the demarcation line that has separated the countries for decades, tensions on the peninsula are escalating rapidly.
In recent days, North Korea has destroyed an inter-Korea liaison office on its side of the border and has threatened military action against the South. Seoul has responded by threatening retaliation against Pyongyang -- moves that have hindered South Korea President Moon Jae-in's policy priority of seeking reconciliation between the countries, which are still technically at war.
Here are seven things to know about the latest developments on the Korean Peninsula:
What is the office that North Korea blew up?
The inter-Korean liaison office was a venue for meetings between the two Koreas. It was located in the North Korean border town of Kaesong in an industrial park the two Koreas set up in 2002 and where South Korean manufacturers employed North Korean workers.
In 2018 and 2019, the two sides held a series of high-profile summits where Moon and North Korean leader Kim Jong Un agreed to work on a series of projects that would reduce tensions. The liaison office was to be where government officials would work out details of the projects, such as the reconnection of railways and joint excavation of remains from the Korean War.
By the time North Korea blew up the building, sending shock waves across the border in the process, the office had been idle for months. South Korea pulled its staff in January due to concerns over the coronavirus, and inter-Korean cooperation had been stagnant for months, with North Korea ignoring the South's calls for dialogue and taking an increasingly belligerent tone.
Why did they destroy the office?
In explaining the destruction of the office, North Korea announced via its official news agency that the move was intended to make "human scum, and those who have sheltered the scum, to pay dearly for their crimes."
The crude language is a reference to North Korean defectors and activists who launch leaflets via balloons into the North containing harsh criticism of North Korea's leadership. The groups have long been a thorn in North Korea's side.
The office was a prominent symbol of inter-Korean cooperation, and by releasing images of its destruction instead of simply leaving it empty, North Korea appears to be sending the message to Seoul that Pyongyang will no longer cooperate with the South, and is back to ratcheting up military tensions.
How is South Korea responding?
The Moon administration has made rapprochement with North Korea a cornerstone policy, but has responded sternly to this week's actions. The South has vowed to respond forcefully to any further provocations.
On Wednesday, the South's presidential office addressed personal criticism of Moon by the North, with one of Moon's secretaries telling reporters, "We solemnly warn that we will not tolerate the North's nonsense words anymore. Such words do not help the North. We hope the North will use basic etiquette from now."
However, the Moon administration is also determined to stop activists from launching any more balloons.
What is the point of these launches?
Activists -- some led by North Korean defectors -- have for years gathered at South Korea's border with the North to launch large balloons filled with leaflets into North Korea.
The leaflets contain information on North Korea's system of government and nuclear weapons programs. In sometimes shrill terms, the leaflets contend that the ruling Kim family oppresses the country's people and cares only about their own comfort and enrichment. This message comes in stark contrast to the North's official narrative that the country's leaders are selfless and focused on protecting the people.
The groups behind the leaflets argue that they are performing a public service by puncturing Pyongyang's strict controls on what information its citizens can access.
Is military conflict a possibility?
North Korea has announced plans to redeploy troops to vacated locations near the border. South Korea's defense ministry has said that the military is closely monitoring the North Korean military for any signs of unusual activity.
The North recently cut all communication with the South, which military analysts say may raise the possibility of accidental clashes, where one side misinterprets routine movements as an act of aggression.
Nevertheless, periods of heightened tensions are a regular occurrence on the Korean Peninsula. Only in extremely rare cases do the two militaries exchange fire.
Why is North Korea doing this now?
North Korea's leadership is currently grappling with the effects of strict international sanctions and the coronavirus pandemic.
While North Korea has not admitted to having any cases of COVID-19, the country closed its only active border, with China, in January. The border is the conduit for much of North Korea's imports. Last week a United Nations special rapporteur said the border closure was worsening conditions for vulnerable groups in the country. The UN's World Food Program told reporters that more than 10 million North Koreans are in need of humanitarian aid.
When times get tough North Korea customarily calls on its people to come together and work harder, blaming outside forces for any problems. This time, Pyongyang may be objecting to the balloon launches in the South to rally its struggling citizens.
What happens next?
For decades, North Korea has toggled between conciliatory and bellicose approaches to the outside world. North Korea could continue to carry out provocations, such as a test of a new weapon, or quietly return to the status quo.
A showdown could come on June 25, the 70th anniversary of the start of the Korean War, when activist groups have pledged to go ahead with balloon launches. Local governments and police are attempting to stop them by declaring oft-used launch sites off-limits. North Korea also sometimes uses major days on the calendar to make announcements or carry out shows of force.