The US and South Korean militaries launched a major show of force in the Yellow Sea Sunday in what is widely seen as both a threat to North Korea and an attempt to intimidate China into ceding to Washington’s position on the escalating crisis on the Korean peninsula.

The war games come just five days after an exchange of artillery fire in the Yellow Sea off North Korea’s coast led to the deaths of four South Koreans, two marines and two civilian construction workers, on the island of Yeonpyeong. They mark a calculated escalation of tensions on the part of Washington, carrying with it the danger of provoking a new and far more dangerous military confrontation.

North Korea issued a statement condemning the exercise as “a very dangerous military provocation” and accused Washington and Seoul of pursuing a “bellicose policy” in the region.

US Forces Korea (USFK) issued a statement asserting that the exercise “demonstrates the strength” of US-South Korean alliance and its “commitment to regional stability through deterrence.”

The potential for an armed confrontation was underscored by two events on Sunday. In Yeonpyeong, residents and troops were ordered into bunkers after the South Korean military claimed to have heard artillery fire from the north.

And South Korea revealed that its troops had “mistakenly” fired an artillery round toward the heavily fortified Demilitarized Zone that separates North and South Korea. South Korean military authorities sent a message to North Korea insisting that the barrage was unintentional and not hostile.

Meanwhile, there were reports from the North that both surface-to-air and surface-to-surface missiles had been deployed on their launching pads in response to the US-South Korean exercise.

Leading the live-fire maneuvers is the US nuclear-powered aircraft carrier, the USS George Washington. The 100,000-ton vessel carries some 80 warplanes and a crew of 6,000. It is accompanied by several other destroyers and other warships as well as an E-8 Joint Surveillance Target Attack Radar System, a flying command and control aircraft that is capable of carrying out precise surveillance of movements of North Korean ground forces, aircraft and surface-to-surface missiles.

The large-scale war games are to last for four days. It marks the second time in little more than four months that the USS George Washington has been deployed off the Korean coast. Last July, it participated in joint maneuvers with South Korean naval forces in another show of force mounted in response to the sinking last March of the South Korean warship, the Cheonan, in which 46 sailors lost their lives. The South Korean government blamed Pyongyang for the sinking, but North Korea denied any involvement.

Those military exercises had also been planned for the Yellow Sea, to the west of the Korean Peninsula and close to Chinese mainland, but were shifted to the Sea of Japan, to the east of the peninsula, in the face of angry protests from Beijing that US war games in the Yellow Sea posed a threat to Chinese security.

Beijing issued somewhat more muted warnings this time around, asserting its rejection of any military maneuvers that infringed on its exclusive economic zone, which extends 200 miles from the Chinese coastline.

While the exercises are reportedly being held over 70 miles south of the disputed Northern Limit Line, the maritime border unilaterally imposed by the US military at the close of the Korean War, it still marks a deliberate US flouting of Beijing’s concerns and a ratcheting up of US-China tensions.

China has launched its own diplomatic offensive, dispatching an envoy to Seoul and calling in the US ambassador in Beijing for discussions. It has called for “emergency consultations” in Beijing early next month.

“The Chinese side, after careful deliberation, proposes emergency consultations among the heads of delegation to the Six-Party Talks in early December in Beijing to exchange views on major issues of concern to the parties at present,” said Wu Dawei, China’s special representative for the Korean Peninsula.

The Six-Party Talks, which were organized to discuss the denuclearization of the Korean Peninsula, include the two Koreas, the US, China, Russia and Japan. They have been suspended since December 2008. In the face of the Obama administration’s policy of “strategic patience,” which translates into maintaining punishing economic sanctions against North Korea while making no serious effort to resume the negotiations, North Korea carried out a second nuclear test last year and, earlier this month, took a US scientist on a tour of a modern new centrifuge plant that has the potential to create highly enriched uranium suitable for nuclear weapons.

While China has consistently pushed for a resumption of the talks as a means of defusing tensions in Northeast Asia, Washington has seen the nuclear issue as a useful means of exerting pressure not only on North Korea, but on Beijing itself.

This US position was echoed by the South Korean government following talks Sunday between President Lee Myung-bak and Chinese envoy Dai Bingguo in Seoul. After two hours of discussion, the South Korean government issued a statement demanding that China adopt “a fair and responsible attitude” toward the Korean crisis.

The South Korean press reported that Lee rejected the call for the crisis talks in Beijing on the grounds that it was not the “right time.” Seoul and Washington have demanded that North Korea offer concessions on its nuclear program in advance of any resumption of the six-party negotiations.

The Japanese government adopted a similar position. “We will coordinate with the relevant countries, in particular South Korea and the US, but our position has always been that we do not want to talk just for the sake of talking,” the Japanese Foreign Ministry said. “There has to be some action on the North Korean side… Given recent developments, we will have to consider [the Chinese proposal] cautiously.”

In Washington, top officials expressed a similar rejection of the Chinese proposal. Admiral Michael Mullen, the chairman of the Joint Chiefs of Staff, described himself in an appearance on CNN as “one who believes we shouldn’t be rewarding bad behavior here.”

Mullen also demanded that Beijing follow Washington’s policy in placing redoubled pressure on Pyongyang, which depends upon China for most of its trade and fuel. “It’s hard to know why China doesn’t push harder,” the US military commander said. He warned that unless action was taken, North Korea would eventually be able to develop “a ballistic missile capability which will threaten the United States and others.”

Even more bellicose were statements Sunday by US Republican Senator and former presidential candidate John McCain of Arizona, who declared on CNN, “I think it’s time we talked about regime change” in North Korea. McCain likewise demanded Chinese action against North Korea, charging that “China is not behaving as a responsible world power.”

“Responsibility” apparently would involve Beijing tightening the economic noose around North Korea with the aim of bringing about the country’s implosion and the collapse of the government in Pyongyang. For China, this would pose the threat of waves of refugees seeking to cross into its territory and the removal of a strategic buffer state that could end up with the deployment of US ground troops on its border, the same border along which it fought US troops 60 years ago.

Likely to heighten tensions in the region and Beijing’s concerns still further is one of the confidential State Department documents posted by WikiLeaks Sunday. It cited US and South Korean officials “gaming out an eventual collapse of North Korea.” Reportedly this included proposals for South Korean offers to Beijing of “commercial inducements” to “help salve” China’s “concerns about living with a reunified Korea” that is in a “benign alliance” with the United States.