N. Korea's firing at US spy plane tests American resolve

The United States will take "whatever steps are necessary" to protect both planes and pilots on continuing spy missions near the demilitarized zone separating North and South Korea.

That hint, by a US State Department spokesman, of possible military retaliation was made Aug. 27, one day after announcement that a North Korean surface-to-air missile had been fired at an American SR-71, an advanced high-altitude, high-speed surveillance aircraft on a mission near the demilitarized zone. But a US Defense Department spokesman added "no specific new preparedness steps are under way."

The warning, about a week after US planes shot down two Libyan jets in disputed waters off the Libyan coast, served a number of purposes, according to diplomatic and military observers:

* It served clear notice on communist North Korea that further "provocations" could lead to US military retaliation. The Reagan administration does not want a repetition of the aggressive North Korean actions that led to the seizure of the US Navy intelligence ship Pueblo in January 1968.

* It informed the Soviet Union and China that unless they act to restrain their North Korean ally, tensions on the volatile Korean Peninsula could escalate. In another move for this purpose the US government will contact both the Soviet Union and China and ask them to convery Washington's "deep concern" over this "dangerous incident" to North Korea, according to a government spokesman in Washington.

* In the aftermatch of the downing of the Libyan jets, it reinforced a worldwide "message" that the United States might use military force against anyone who tested "its will to fight". The desire to emphasize American determination is apparently aimed both at small states like Libya and North Korea, and at Washington's chief adversary, the Soviet Union.

* To gather public support in the US against efforts to cut the American defense budget. Both Libyan and Korean incidents fuel the arguments of those who say cutting the US defense budget might weaken America's ability to meet armed threats.

A State Department spokesman says firing of the North Korean missile in an effort to bring down the US plane "has nor precedent in the recent past." Previously, he says, the North Koreans had confined themselves to verbal protests over spying activities by such planes.

The spokesman declined to speculate over why the North Koreans decided to fire a missile at this time.But experts outisde of government have frequently pointed out that North Korea periodically tests the resolve of United States forces based in South Korea.

Coincidentally or not, the missile firing coincided with renewed publicity for Kim Jong II, widely regarded as the heir apparent to his father, Kim II Sung , as President of North Korea. The younger Kim has started to make public appearances for the first time in a year, according to reports monitored in Tokyo.

Most significant Kim Jong II's rise hasl sometimes been taken to coincide with emergence of a more militant hard-line policy toward the United States. For example, after wielding some influence in North Korea affairs, he fell from public attention in 1975-76 following the tough US response to the killing of Two American soldiers in the demilitarized zone. This raised speculation in the West that a hard-line approach by Kim Jong II had been blamed for the incident.

Meanwhile the American-led United Nations Command in Korea called for an Aug. 29 meeting of the Military Armistice Commission, presumably to discuss the issue. One US spokesman said North Korea, in line with past practice, was expected to counterpropose an alternate date for the meeting.

Some 38,000 US troops are stationed in South Korea to help defend against invasion from the north. Six hundred thousand North Korean ground troops face 520,000 South Korean troops.