President Roh Tae-woo of South Korea extended an olive branch this week that could do much to help reduce tensions in one of the world's major trouble spots.

If accepted by North Korea, the offer could improve relations not only between Seoul and Pyongyang, but also between Pyongyang and Washington and Tokyo, South Korea's main allies.Basically, the offer means that the government of Seoul is willing to cast aside 40 years of Cold War animosities in favor of humanitarian exchanges, a diplomatic thaw, economic ties and, eventually, reunification of the two Koreas.

Though lacking in specifics, the offer is still significant for its reversal of South Korea's longstanding policy of striving to drive North Korea into isolation from the international community.

While the offer was made 72 days before the opening of the Summer Olympics in Seoul, it would be a mistake to see much significance in that timing. It's almost certainly too late to persuade North Korea to abandon its boycott of the Olympics and send competitors to Seoul in September. Besides, North Korea is boycotting the games because its demands to co-host the Olympics have not been met, nor should they be because the invitation to host the games was extended only to South Korea.

Meanwhile, Seoul has launched a potentially important diplomatic initiative. Its acceptance or rejection can determine the quality of life in both North and South Korea for many decades. If Moscow is really as interested in world peace as it professes to be, it will urge its allies in Pyongyang to respond to this initiative constructively.