American Secretary of State George Shultz took a break from striped-pants diplomacy here and donned a fur-lined parka near the demilitarized zone dividing the two Koreas.
Mr. Shultz's main job for the past two days has been to reassure South Korea of American support.
American relations with South Korea have rarely been better than they are now. But periodic visits and pledges of support by high-level American officials are part of an established ritual.
Shultz's main business on his current trip to East Asia was in China and Japan. But he could hardly pass through the region without paying a visit to an old ally of the United States, South Korea. And he could hardly come here without flying up to the demilitarized zone (DMZ).
Shultz was told in a military briefing that North Korea's military buildup during the 1970s had resulted in at least a doubling of most elements of that communist nation's military strength. Compensating to a degree for this, the Americans and South Koreans hold the edge over the North Koreans in fighter aircraft.
American army officers told Secretary Shultz that in case of attack, the main aim of the combined field army of American and South Korean troops was to defend Seoul and to defeat the North Koreans as far forward as possible.
''Our mission is to fight here until the last man,'' a Korean Army colonel told Shultz in freezing weather at a strong point overlooking the mountainous DMZ.''There will be no withdrawal from here,'' said the colonel, who never ceased standing stiffly at attention.
Shultz then met with a small group of American Army Rangers, their faces blackened in preparation for a night patrol. After hearing of the men's mission and looking at their equipment, Shultz said: ''We're proud of what you're doing here. . . . President Reagan is very conscious of what you're doing up here. You have his full support.''
The secretary of state returned to Seoul by helicopter. According to the State Department spokesman, John Hughes, Shultz was impressed by his trip to the DMZ, feeling that everyone ought to visit it.
In his meetings with Korean officials, including South Korea's President Chun Doo Hwan, Shultz reaffirmed the US commitment to the defense of South Korea.
According to State Department officials, Shultz took up the question of human rights violations in South Korea with President Chun. Shultz thinks Chun has made progress on the human rights front through the release of political prisoners and preliminary steps toward a liberalization of the political system.
More than 350 political prisoners remain under detention in South Korea. There have been widespread reports of torture in the prisons. The Korean press is highly restricted in what it can publish.
''The most important thing is for the American government to put pressure on this government to give us freedom of the press,'' said a prominent Korean dissident here, who asked not to be identified. ''The government says all sorts of things about democracy. . . . But it's all a farce unless they give us freedom of the press.''