Straddling between peace and conflict According to Time, "The North does not recognize the border that was unilaterally drawn by the United Nations at the close of the 1950–53 Korean War.

"[10] Under the armistice, the United Nations has designated five Northwest Islands to remain within its jurisdiction - Baengnyeongdo, Yeonpyeongdo, Daecheongdo, Socheongdo, and Udo.

These islands strategically lie in the Yellow Sea just off the North Korean coast, causing disputes over their control and posing a persistent security threat to South Korea.

[9][13] Later, after 1982, it also hindered North Korea establishing a United Nations Convention on the Law of the Sea Exclusive Economic Zone to control fishing in the area.

As part of this agreement, areas surrounding the Northern Limit Line were designated as a maritime peace zone, intended to prevent accidental military clashes and ensure safe and sustainable fishing activities for both countries.

The 2010 exercise involved 70,000 troops from all four branches of the South Korean military, equipped with 600 tracked vehicles, 90 helicopters, 50 warships, and 500 aircraft.

[26] It had originally been intended that the United States Navy and Marine Corps would participate in a joint amphibious exercise in the Yellow (Western) Sea, west of South Korea.

However, the US pulled out of the joint exercise citing "scheduling conflicts",[27] though South Korean observers suggested that the real reason was the opposition of China, which regards a large portion of the Yellow Sea as its own territory.

[31] South Korean Minister of National Defense, Kim Tae-young, said the firing was not part of the Hoguk exercise, but was a separate routine monthly drill carried out 4–5 km away from the NLL,[32] contrary to previous media reports.

Many of the shells landed on a military camp, but others hit the island's principal settlement, destroying numerous homes and shops, and starting fires.

Two South Korean marines, Hasa (Staff Sergeant) Seo Jeong-wu and Ilbyeong (Lance Corporal) Moon Gwang-wuk, were killed.

According to the local county office, 70 percent of the island's forests and fields were burned and 21 houses and warehouses and eight public buildings were destroyed in the bombardment.

It suspended interchanges with the North, cancelling inter-Korean Red Cross talks and banning visits to the jointly operated Kaesong Industrial Region.

He called for "the two Koreas to begin talks to prevent the situation from worsening" and urged the government to protect the peace and safety of South Koreans.

[40] On 25 November, South Korea's defense minister, Kim Tae-young, announced his resignation after he was criticized for leading a response to the incident considered too passive by members of both the ruling and opposition political parties.

[64] President Lee instructed the South Korean military to strike North Korea's missile base near its coastal artillery positions if there were an indication of further provocation.

[65] Lee Hong-gi of the JCS told the media that the attack had been a "premeditated, intentional illegal violation of the U.N. Convention, the Armistice Agreement and the inter-Korean non-aggression accord.

"[66] On 24 November, the US aircraft carrier USS George Washington departed for joint exercises in the Yellow Sea with the Republic of Korea Navy, in part to deter further North Korean military action but also to "send a message"[67] to China.

[33][71] One year after the event the South Korean military presence on the island had been substantially increased with the deployment of more K-9 howitzers, K-10 automatic ammunition re-supply vehicles, 130-millimeter, 36-round, truck-mounted Kooryong multiple rocket launchers and AH-1S Cobra attack helicopters.

Robert Kelly, an assistant professor at Pusan National University in South Korea, says that Seoul's increasing global stature may have provoked Pyongyang.

Kim and his son were reported to have visited the Kaemori artillery base, whence many of the North Korean shells were fired, the day before the attack.

"[76][77] In 2014, Robert Gates, who was United States Secretary of Defense during the incident, wrote in his memoirs that the South Korean government planned a "disproportionately aggressive" military retaliation "involving both aircraft and artillery".

Gates said he, US President Barack Obama and Secretary of State Hillary Clinton had numerous telephone calls with South Korean counterparts to deescalate tension.