Red Sea crisis boosts US.

If any Middle East crisis can be said to be a ''good'' one, the apparent mining of the Red Sea is so far turning out just that way for the West. This could change. The Red Sea explosions, which have reportedly caused only limited damage to ships and no human casualties, could eventually bring more serious harm.

Or, on the political front, the leading Western - and American - role in responding to the crisis could be diluted by a Soviet involvement of the sort American policymakers have tried with great success to limit for the past decade and a half.

After all, just outside the southern gateway of the Red Sea - near a part of the waterway affected by the mine explosions - lies the People's Democratic Republic of Yemen, the only Soviet-style Marxist state in the Arab world and a close protege of Moscow.

And several East-bloc cargo ships - Soviet and Polish - figure among the roughly 15 affected by the Red Sea explosions since they began last month.

Yet at time of writing, the closest the Soviets had come to involvement in a widening international effort to defuse the mines literally and politically was a British news agency report late last week that a Soviet mine-sweeping craft would soon join the efforts. There has been no subsequent public sign such a ship has arrived.

So far, the mines crisis has differed strikingly from the last major occasion for American and allied involvement in the Mideast - the Lebanon crisis. That one ended, for the West, with what amounted to a forced pullout of peacekeeping troops from the United States, Italy, Britain, and France about five months ago.

The following elements have been important in making the Red Sea crisis, at least so far, a comparatively ''good'' one for the West:

* The very fact that key Red Sea coastal states - notably Egypt and Saudi Arabia - have openly sought US and other Western help. At the time of the Americans' artfully entitled ''rede-ployment'' of Marines from Lebanon, there were loud rumblings from such relatively pro-Western states that the move might cause serious, long-term damage to US stock in the region.

* The mines have proved, so far, to be a far less daunting foe than the assortment of well-armed troops, suicide truck-bomb drivers, and hilltop artillery positions arrayed against the US presence in Lebanon. There still is no completely clear indication of what, or who, has been behind the Red Sea explosions.

But a report Tuesday quoting the authoritative Lloyd's shipping-intelligence service in London seemed to reinforce earlier speculation that rather primitive surface mines have been responsible. The report said three such mines had now been sighted, undetonated, in the Red Sea.

As for the ''who'' of the mystery, the only clue is a telephoned claim of responsibility by the self-styled Islamic Jihad organization. This is a pro-Iranian group - or telephone voice - that made similar claims in connection with truck-bomb strikes in Lebanon. The phone caller said nearly 200 mines had been placed in two Red Sea areas - the Suez Canal to its north, and the Bab al Mandab strait to its south.

* The West - again, at least so far - has been able to set its own pace of involvement in the Red Sea crisis. In Lebanon, this was rarely true. War called the tune - whether, initially, in the shape of the massacres of Palestinians in Beirut's Sabra and Shatila refugee camps; or of a mounting series of violent assaults on US marines; or the steadily eroding power of Lebanon's US-propped regime in the weeks preceding the Western retreat.

But this time around, there has been an almost ostentatiously measured pace to the Western response. It has been firm. It has also been gradual, starting with appropriate public statements, then dispatch of US mine experts to Cairo, then a declared wait for a formal Egyptian request for any further involvement. It is only now that a de facto task force involving US, British, and French anti-mine vessels is taking shape in the Red Sea. Italy apparently is also about to join.

With an increasingly watchful international eye being kept on the Red Sea, the question now is whether the mine explosions might still escalate.

Although this is impossible to predict with certainty, logistic considerations suggest that whoever has apparently planted surface mines will be hard pressed to get away with much more than dropping a few more.

Egypt, for its part, has accused rivals Iran and Libya with complicity in the explosions. One Libyan vessel, and at least two Iranian ones, reportedly passed through the Red Sea not long before the explosions began.

Both states have denied involvement. In Iran's case, this came in the shape of a statement by Islamic leader Ayatollah Khomeini last week both denying involvement and rapping his own country's official radio for applauding the mining as an indication of the impotence of ''arrogant'' outside powers.