South Korea warns North Korea after artillery barrage

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South Korea threatened Tuesday to deal “sternly” with continuing provocations from Pyongyang, calling the North's artillery barrage on Monday a violation of the terms of their cease-fire agreement.

Tension has escalated dramatically on the Korean peninsula since the sinking of South Korean ship Cheonan on March 26, which the South blamed on a torpedo shot from a North Korean submarine. After the sinking, the South waited nearly two months for the results of a five-nation investigation into the incident before officially blaming the North, and that measured response was followed with a gradual increase in military posturing.

The South’s statement Tuesday is the latest uptick in tension. It comes in response to the North’s firing of at least 110 rounds of artillery off its west coast Monday. Most landed in North Korean waters, but the Associated Press reports that about 10 shells crossed the disputed maritime border, landing near an inhabited island in the South.

The South Korean Defense Ministry said Tuesday "If North Korea continues its provocative rhetoric and acts, we will deal sternly with them,” according to the AP. The words echoed its promise with the US last year of a "stern, united response" to any rocket launch by North Korea.

In response, North Korea on Tuesday threatened a war of retaliation.

The Wall Street Journal reports that the North's firing of rockets Monday displayed one of its greatest threats to the South:

The artillery firing is one of the few military actions North Korea can take that spawns headlines in South Korea, but doesn't produce much criticism from Seoul or anger other countries, analysts say. North Korea has for decades possessed a huge cache of rockets and artillery that could damage much of the South.

"One of the foremost threats North Korea has is its long-range artillery," says Kim Byung-ki, a political scientist at Korea University in Seoul. "It's a show of force that is designed to threaten and coerce us without provoking a serious response."

On Sunday, the North seized a South Korean squid-fishing boat and has detained the four South Korean and three Chinese fishermen, as The New York Times reported. Both the seizure of the boat and the artillery barrage are seen as responses to the five-day South Korean naval exercise off the east coast that ended Monday, which itself followed four days of joint US-Korean military exercises off the west coast.

Reuters reports that despite the South’s rhetoric, there is little more it can do to respond to the North’s provocations, since it has made clear that it will not respond militarily. Options include more military exercises or halting participation in the Kaesung Park joint industrial complex, which helps cash-starved North Korea. The South already reduced business ties and cut off aid to North Korea following the Cheonan sinking.

But The Korea Times, based in Seoul, reports that another option for the South is resuming propaganda broadcasts on the border with the North. The anti-communist messages, broadcast over loudspeakers at the border, on billboards erected on the border, or in leaflets dropped into the North, have angered the North in the past. The South planned to resume them after the Cheonan sinking, but delayed the move.

The Korea Times reports that defense ministry officials said the South may now go ahead with the plan in light of the North’s recent actions.

The fate of the captured fishermen, however, will likely factor into the South's decisions. The Christian Science Monitor reports that the South fears the North will use them as bargaining chips:

The longer the North held the boat and its crew, however, the more likely it seemed that at least some of them might be held as pawns in the larger struggle over disputed waters on both sides of the Korean peninsula. Officials said the boat may have been picked up inside the North’s “exclusive economic zone” off its east coast, but there’s no confirmation of that.

North Korea was expected to deal far less harshly with the crew’s three Chinese members in view of the North’s reliance on China as its only real ally.

The New York Times reports that such incidents of captured fishing boats happen occasionally, and “how fast they were released often depended on the tenor of bilateral relations at the time.” That does not bode well for the fishermen currently held by the North, with tension at a boiling point.