North Korea nuclear test
On February 12, 2013, North Korea unleashed its third - and largest - underground nuclear test, causing an earthquake with a magnitude of 4.9. The Foreign Ministry in Pyongyang said the test was the "first response" to what it called US threats. The test defied a UN move tightening sanctions against leader Kim Jong-un's regime three weeks before. The UN Security Council strongly condemned the test and vowed to take action against Pyongyang for an act that all major world powers, including traditional ally China, denounced.
Latest crisis has some South Koreans looking at the threats more seriously
Blustery North Korean threats are normally disregarded, but some residents now appear to be taking the latest escalation more seriously
Andrew Salmon in Seoul
While most South Koreans shrug off North Korean threats with their customary "so what?" attitude towards the threatening regime, some signs suggest the rolling crisis in North-South relations is causing at least some nerves to fray.
On Tuesday, the top trending item on Naver, Korea's most popular web portal, was survival kits - personal packages featuring such items as bottled water, message pads, emergency rations and fire-starting equipment.
There also appears to be some stockpiling of crisis supplies. Online retailer G-Mart reported that it had seen a 227 per cent rise in sales of preserved noodles, a 177 per cent increase for bottled water, and a 117 per cent rise in tinned products since the crisis began.
Reflecting military tensions, military-themed shows are enjoying rising popularity in what CJ E&M, South Korea's largest entertainment production company, dubs "The Korean Military Wave".
Blue Tower, a sitcom set on an army base, has been one of the top-ranked cable shows since it started airing in late January.
On YouTube, Les Militarables, a 13-minute parody of hit musical Les Miserables that was produced by South Korea's Air Force - has garnered 4.38 million views since being posted on February 5.
And an armed forces-backed musical, The Promise, that commemorates the 60th anniversary of the end of the Korean war, has won attention as it stars boy-band star Lee Tee-uk, who is currently doing military service.
Signs of unease and interest in things military are unusual for South Koreans, who have grown weary of North Korea and routinely discount its threats.
"My sense is that this is more worrying than previous crises," said Karl Friedhoff, who monitors public opinion at the Asan Institute, a Seoul think tank, and who noted that the South Korean government is reportedly preparing evacuation plans for schools in the event of an attack.
The current crisis was sparked by a missile test in December, reignited by February's nuclear test and now simmers on, following Pyongyang's revocation on Monday of the armistice that ended hostilities in the 1950-53 Korean war.
An Asan survey at the end of 2012 found that Koreans in every age group believe the chances of war are now over 50 per cent.
"On the surface it is very placid, but I think there is an expectation that there has been a threat, now there is a period of calm, then there will be an attack," Friedhoff said.
Calm certainly seems prevalent at present. Capital markets have been largely unaffected, and Seoulites continue to go about their normal lives.
"It is the usual thing, every year when the 'Key Resolve' exercise happens," said Kim Hyun-jin, a staffer at a marketing firm in central Seoul, referring to ongoing South Korean-US military exercises. "I just see everything they do as begging more money from us or the United States - no more than that."
Informed observers are more worried about Seoul or Washington's response to a limited attack by Pyongyang, than of Kim launching all-out war.
"I am a little more concerned than normal," said Jack Burton, a columnist for The Korea Times. "I have always been afraid that things will start from the South Korean or American side - if the North Koreans launch another military provocation, the response could escalate."