REPORTS of mass public executions and the flight of thousands of refugees into China are fuelling fears in the Japanese government about the imminent collapse of the North Korean regime.
Since disastrous floods last summer which washed away homes and severely damaged an already feeble rice harvest, foreign governments have been speculating that widespread food shortages could trigger a sudden collapse in the secretive Stalinist state.
Japan's foreign ministry is investigating claims that thousands of refugees, who have fled into China throughout the bitter North Korean winter, are being forcibly repatriated.
US intelligence has reported mass public executions of criminals. North Korean defectors to Seoul regularly bring back lurid accounts of concentration camps, suggesting that the Pyongyang regime is increasingly resorting to repressive measures to contain unrest caused by food shortages.
After an unprecedented appeal last autumn for food supplies, North Korea is now showing signs of becoming uncomfortable with the presence of international aid agencies which have caused more information about the country's potential instability to leak out abroad.
Earlier this month the military stepped in to veto a further appeal for assistance through UN bodies.
Pyongyang's million strong armed forces, concentrated near the demilitarised zone which divides the two Korcas are the principal focus of regional anxiety.
"The extent of their difficulties is hard to read, but there have been suggestions that their military strength cannot be kept at present levels and that it may be eaten into," said a foreign ministry official. "South Korea is very concerned that the North may act our of desperation."
So unfathomable is the Pyongyang regime, however, that it has caused disagreement about its intentions not only between neighbouring countries, but among different agencies of the Japanese government. A conflict on the Korean peninsula would put Tokyo in a desperate dilemma, torn between its concerns for regional security and the demands of its pacifist constitution which completely rule out the dispatch of Japanese combat troops overseas.
"We believe that North Korea is about to collapse, and that a crisis is imminent," a defence ministry official said. "If war broke out between the south and north, the allies would win but South Korea and the US would suffer considerable losses and Japan would also be affected."
Overt military cooperation between Tokyo and Seoul is problematic because of lingering historical resentment about Japan's 35 year colonisation of the peninsula.
In recent weeks, however, senior defence officials from both countries have met regularly to coordinate their response to a North Korean upheaval.
"South Korea believes it will be later than the Americans and Japan assume," the defence official said.
"But we've agreed we should be prepared for possible invasion, guerrilla fighting, limited invasion or a full scale Korean war.