When Secretary of Defense Leon Panetta was in Hawaii last week, he was asked why the U.S. still has troops in South Korea when North Korea’s conventional forces are in miserable condition, South Korea’s soldiers are fully capable of defending their own country, and U.S. forces are experiencing serious budget restrictions.

Mr. Panetta, in a roundtable discussion with reporters, did not disagree with the premise of the question but neither did he confront it. Instead, he said U.S. forces, which have been stationed in Korea since the end of the Korean War in 1953, would remain there to help defend South Korea and to show the American flag in Asia.

“We are a Pacific power, we’re going to remain a Pacific power, and in order to do that, we need to have force projection in the Pacific,” he said. “We maintain those forces not only to help in the protection of South Korea but also as a force to indicate that the United States is going to always maintain a military presence in the Pacific.”

Yet evidence abounds that the North Korean army is incapable of invading South Korea with any chance of success. “They just can’t attack the South,” said a US military officer with access to intelligence assessments. “They can’t do anything like 1950,” said another officer referring to the invasion that started the Korean War.

The Director of National Intelligence, retired Admiral Dennis Blair, said in 2010 that the capabilities of the [North] Korean People’s Army (KPA) “are limited by an aging weapons inventory, low production of military combat systems, deteriorating physical condition of soldiers, and reduced training.”

Blair, who commanded U.S. forces in Asia and the Pacific as head of Pacific Command in Hawaii from 1999 to 2002, continued in a threat assessment: “Inflexible leadership, corruption, low morale, obsolescent weapons, a weak logistical system, and problems with command and control also constrain KPA capabilities and readiness.”

The admiral asserted that South Korean military power far outweighed that of the North. “The conventional military capabilities gap between North and South Korea has become overwhelmingly great and prospects for reversal of this gap remote,” he said. Officers with access to current intelligence said the KPA had deteriorated even more today.

For that reason, Blair asserted that “Pyongyang relies on its nuclear program to deter external attacks on the state and to its regime.” He said that “redressing conventional weaknesses is a major factor and one that Kim and his likely successors will not easily dismiss,” referring to the late Kim Jong Il and his son and successor, Kim Jong Un.

An exception, according to many officers: North Korean artillery, even though armed with obsolete, badly maintained guns fired by poorly trained crews, is deployed close to the demilitarized zone that divides the two Koreas and could inflict many deaths and serious damage before they were silenced by South Korean artillery and air power.

The main reason for the deterioration of the KPA, which, like China’s People’s Liberation Army, includes all of their nation’s armed forces, is economic. Poor crops have caused widespread malnutrition. Idle industry means weapons, equipment, and spare parts are not turned out. Lack of fuel keeps tanks parked and planes grounded.

Particularly important, training has been sorely neglected as troops are either busy foraging for food or trying to repair aged equipment or lack energy to go on maneuvers. Fighter pilots, for instance, are lucky if they get 20 hours in the air in a year compared to 20 hours a month US Air Force and Navy fighter pilots fly.

Because North Korea poses less of a threat, the U.S. has been quietly cutting its forces on the peninsula to fulfill commitments elsewhere. President Lee Myung Bak, reflecting a fear among hawkish Koreans that the U.S. would pull out of Korea, persuaded President George W. Bush in 2008 to set a floor of 28,500 American troops posted there.

The Pentagon, however, has not published figures on US troops in Korea since the end of 2008, when 24,665 were on duty there. US officers said the number now was well under 28,500. In contrast, the Pentagon has published figures on troops stationed in every other country including 7 in Laos and 3 in Mongolia at the end of 2011.

Whatever the case, U.S. and South Korean leaders seem content to leave things as they are because they see time on their side. The condition of North Korea’s forces will only get worse and then, barring a Pyongyang miscalculation and desperate attack on the South, most likely will collapse and take the dictatorial Kim regime down with them.