Seoul — In Korea, as in Europe, deterrence is the name of the game. ''That's our single-minded purpose,'' said United Nations Commander Gen. John A. Wickham - ''to deter war.''
Faced with a continuing buildup of offensive military capacity by North Korea , the United States and South Korea have been upgrading their own joint defenses.
One of the Reagan administration's first acts was to cancel the Carter administration's plans for gradual withdrawal of American ground troops from the Korean Peninsula. President Carter suspended his withdrawal plan after the Soviet invasion of Afghanistan. President Reagan canceled it.
Among other deterrence items ticked off by General Wickham are: A squadron of A-10 antitank bombers is arriving in Suwon in January next year as a ''permanent military addition'' to the American presence in South Korea.
F-16s have been stationed in South Korea, backed up by F-15s on Okinawa.
The Army has brought in tank-killing helicopters and 155-mm howitzers.
Command and control facilities have been improved and hardened, and a new intelligence division provides more effective monitoring of North Korean activities.
The South Korean Army is improving its antitank capabilities, its mobility, and its command and control facilities. South Korea's Air Force will start co-assembling the F-5 ''freedom fighter'' next year, while its Navy is receiving more modern patrol craft.
General Wickham praised the 600,000-man South Korean armed forces as ''among the best in the world, professionally trained and equipped, tough, and dedicated to defending the Republic of (South) Korea at all costs.''
He spoke in an interview at the combined forces' headquarters here, which is also the United Nations command headquarters. Outside, a band played and the honor guard went through its paces. The guard includes not only South Korean and American troops but also British, Philippine, and Thai elements. The multinational component of the honor guard is a reminder of the combat role 16 United Nations members played during the Korean war and a symbol of the continuing United Nations commitment here.
The combined forces command, set up in 1979, is more than a symbol. It brings American and South Korean forces together under an American commander and a South Korean deputy commander.
Unlike the NATO command, which has no troops in peacetime, General Wickham, as combined forces commander, has under his day-to-day control not only the approximately 39,200 American troops and airmen assigned to Korea, but also half a million South Korean combat troops.
As commander, General Wickham's immediate preoccupation is not the Soviet Union but North Korea, a nation of only 17 million people but one of the world's tightest communist dictatorships, whose leader, Kim Il Sung, is seen as dedicated to the unification of Korea by any means, including military force.
General Wickham says that, because of the Sino-Soviet quarrel, North Korea is able to bargain with both Peking and Moscow for military support.
As a result, over the years North Korea has built up the communist world's fourth-largest Army. Its 600,000 to 700,000 ground troops outnumber South Korea's 520,000, and it has three times as many tanks as the South.
North Korea has the world's largest ranger commando force, totaling 100,000 men, General Wickham said. The express purpose of these commandos, the general said, is to infiltrate South Korea by land, air, and sea, to sabotage, kill, and sow confusion in rear areas.
North Korean tunneling under the demilitarized zone is already well documented. General Wickham's headquarters believes that the tunneling continues , although as the North Koreans dig deeper, their work becomes more difficult to uncover.
Will the American and South Korean response ever manage to catch up with the North Korean buildup?
''We don't have to achieve equality,'' said General Wickham. ''We do need to keep working on a mix of military capabilities that provides a balanced defensive might sufficiently powerful to make the risk of initiating a war too high for North Korea.'' In short, adequate to maintain deterrence.