Deployment of the SA2 Guideline and SA6 Gainful antiaircraft missiles in Lebanon would give the Syrians a one-two punch against Israeli warplanes and escalate the air war over that torn land in the process.

The SA12 is the high-altitude missile that knocked Gary Powers' U2 spy plane out of Soviet sky in 1960, to the consternation of the Central Intelligence Agency which had assured president Eisenhower that the U2 would be safely out of reach of the weapon.

On the basis of secret photographs of the SA2, CIA analysts concluded the fins of the missile were too small to give it the required accuracy in the thin air where the U2 flew in the late 1950s, cameras clicking above Soviet military installations.

The SA2 also was used heavily by the North Vietnamese against U.S. aircraft during the Vietnam War. Countermeasures developed against what the pilots called "flying telephone poles" were shared with the Israeli Air Force, greatly reducing the threat of the SA2. Electronic countermeasures installed on Israeli aircraft in recent years almost certainly make the SA2 less of a threat today than during the 1970s.

The North Vietnamese, besides trying to hit U.S. planes at medium and high altitudes with the SA2, used the missile to drive planes down to lower altitudes where conventional antiaircraft guns could reach them.

The SA6 is a newer missile, first shown off at Moscow in 1967 and given to the Egyptians who employed it with deadly effectiveness in the early days of the Arab-Israeli War of 1973. The missile can be ordered into the target aircraft either by radio commands from the ground or by internal homing devices.

Although the Israelis have been working on ways to counter the SA6, this newer missile represents a greater threat than the SA2, particularly if the Syrians should deploy Long Track radar to buttress the Straight Flush radar units which usually accompany the missile into battle.

Although both missiles are mobile, the SA2 is cumbersome to transport because of its size: more than 30 feet long. Typically, the Soviets tow only one SA2 on one trailer. The SA6 is about half that length, enabling a modified tank to carry three at once.

Both missiles can fly out on a slant pattern to about 25 miles. Their vertical reach is estimated to be about 60,000 feet.

How much the SA2 and SA6 missiles escalate the air war over Lebanon will depend in large measure on how many are deployed and what defenses are put around them.