SEOUL • One year after North Korea and South Korea vowed to resume a constructive dialogue, they have instead resurrected a spirit of Cold War-era antagonism, complete with cross-border propaganda shouting matches, spy messaging and defection dramas.
Official contact between the two Koreas has never been easy, but the current situation, with all official lines of communication severed and a host of flashpoint issues raising tensions, appears to be particularly volatile and fraught with risk.
"The relations between North and South Korea have never been as tense as they are now since the Cold War period of the 1970s," said Professor Kim Yong Hyun, a North Korean expert at Dongguk University.
High-profile defections are suddenly back in vogue, with the North Korean deputy ambassador to Britain, Mr Thae Yong Ho, handing Seoul a propaganda coup this week by defecting to South Korea with his family.
Although Mr Thae's motives were probably as much personal as ideological - he has two children, one of school age - South Korean officials have attributed his decision to a straightforward choice between good and evil.
On his reasons for defecting, Mr Thae "cited disgust with (North Korean leader) Kim Jong Un's regime and admiration for South Korea's free, democratic system", said Unification Ministry spokesman Jeong Joon Hee.
This sort of old-school diplomatic baiting has become increasingly common at a time of almost zero cross-border contact.
As tensions rose in the wake of North Korea's fourth nuclear test in January, Pyongyang shut down the two existing hotlines with South Korea - one used by the military and one for government-to-government communication.
And last month, it severed its only direct communication link with the United States when it shut down the so-called "New York channel", which had previously served as a key point of contact between North Korean and US diplomats at the United Nations.
"The total absence of channels for dialogue between the two Koreas as well as between Pyongyang and Washington is a real cause for concern," Prof Kim said.
Inter-Korean communication has now gone back to basics, with both sides effectively reduced to shouting across the heavily militarised border.
Banks of loudspeakers have been dusted off and brought up to the front lines, blasting music and propaganda messages into each other's territory.
In another nod to Cold War methodology, North Korea appears to have resumed the transmission of coded messages over state radio - presumably meant for spies operating in the South.
Tensions are expected to spike again next week when South Korea and the US kick off a joint military exercise involving tens of thousands of troops.
But the North might opt for a low-key response this time around so as to avoid undermining a Cold War-flavoured stand-off that has built up over South Korea's recent decision to deploy a sophisticated US anti-missile system on its territory, according to Professor Yang Moo Jin of the University of North Korean Studies.
"Inter-Korean peacetime relations are really at their worst... with trade and exchanges of people and dialogue all severed," said Prof Yang.