A former senior official in President Bush's White House has dropped a proverbial bombshell by asserting that the United States and South Korea have no coordinated plan to cope with a collapse of the North Korean regime of "Dear Leader" Kim Jong-il, a prospect that becomes more possible with each passing day.

Victor Cha, who was director for Asian affairs on the National Security Council staff from 2004 to 2007, wrote last week: "In what would be the single most important contingency that could impact the South Korean economy and security for decades, there is no agreed-upon plan for how to deal with a collapsing North Korea."

In response to an e-mail asking: "Why was no plan drawn up when you were on the NSC staff in the White House?" Cha replied: "There is no lack of planning on the U.S. government side. We've done our part."

Cha, who has returned to Georgetown University in Washington as director of Asian studies, continued: "The issue is that there is no agreed-upon mechanism for bilateral, trilateral or other planning (including China), which obviously should be done in advance of such a contingency."

In an article in the Chosun Ilbo, a leading South Korean newspaper, Cha blamed the former president of South Korea, Roh Moo-hyun, whose term ended in February.

"The Roh Moo-hyun government," Cha said, "rejected planning discussions because it believed such discussions would offend Pyongyang and give the impression the U.S. and Seoul were actively conspiring to collapse the regime."

Cha, a Korean-American who speaks fluent Korean, disclosed the gap between the U.S. and South Korea as mass anti-American demonstrations broke out in Seoul. The issue was supposedly an agreement by the new government of President Lee Myung-bak to permit the U.S. to export beef to South Korea. That seemed to be an excuse for deep-seated anti-Americanism to erupt.

In addition, South Koreans were angered by Secretary of State Condoleezza Rice, who was perceived to have denigrated the U.S. alliance with Korea in an article in the prominent journal Foreign Affairs. Many South Koreans contended that she had dropped the importance of South Korea to America a notch below that for Japan, always a sensitive issue for Koreans whose land was occupied by Japan from 1910 to 1945.

In the event of a North Korean implosion, Cha suggested in his Chosun Ilbo essay that the U.S. "should be responsible for securing all weapons of mass destruction and missiles sites." That would require U.S. armored forces in South Korea to drive north, perhaps reinforced by troops from Alaska and Hawai'i.

At the same time, Cha suggested, Chinese forces would "secure a buffer along the Yalu River to prevent an outflow of North Korean refugees into China." Moreover, those forces "might secure that buffer south (rather than north) of the Yalu in order to be effective."

That raised the possibility that China and American troops might confront each other in North Korea. Cha said, "The key with China in a North Korea contingency is to reduce an uncertainty or potential for misperception." The critical issue, Cha contended, is transparency — "knowing what the other side is doing in a contingency and why they are doing it."

On the potential for a North Korean collapse, Cha was understated. "Kim Jong-il is not getting any younger," he wrote. "The food situation is not getting better." He labeled the authoritarian North Korean political system "brittle."

A pro-North Korean organization in South Korea that calls itself "Good Friends" seeks to generate sympathy for North Koreans by reporting on their plight, which borders on famine. On the Internet, it quoted Kim Jong-Il saying: "There is nothing more important and pressing as resolving the food shortage for the people."

Good Friends, which refuses to disclose the source of its funds or information, said the food crisis is so severe that even military officers, who take top priority under Kim Jong-il's "military first" policy, get only two meals of porridge a day. "This would be the first time in the history of our country that the military is eating porridge," Good Friends quoted a North Korean official as saying.

Moreover, rumors of Kim Jong-il's ill health, or that he had been assassinated, trickle out from Pyongyang. Such gossip led Cha to advocate that the governments of South Korea, Japan, China and the U.S. forge a plan to cope with a collapse.

"It has to be done — and done well," he urged, "before the next rumor proves to be true."

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.