SOUTHEAST ASIA A LOSING PROPOSITION THE WEST'S MANEUVERS TO COUNTER THE DISINTEGRATION IN LAOS LAST WEEK WERE LARGELY DIPLOMATIC . IN LONDON, BRITISH FOREIGN SECRETARY LORD HOME CALLED ON RUSSIA CO-ADMINISTRATOR WITH BRITAIN OF THE GENEVA ACCORDS TO SIGN A JOINT APPEAL THAT THE FEUDING FORCES IN LAOS END THEIR FIGHTING . FEARFUL THAT SUCH PEACE TALK WOULD NUDGE ASIAN COMMUNIST REVOLUTIONARIES STILL CLOSER TO RIVAL RED CHINA AND ITS " HARD LINE, " RUSSIA REFUSED, UNLESS THE STATEMENT SPECIFICALLY BLAMED THE U.S . FOR UNDERMINING THE PEACE IN LAOS . BRITAIN VETOED THE SUGGESTION . PRESIDENT KENNEDY HUSTLED UNDER SECRETARY OF STATE FOR POLITICAL AFFAIRS AVERELL HARRIMAN, WHO HAD HAMMERED OUT THE BASIC FORMAT FOR THE GENEVA AGREEMENT LAST SUMMER, TO MOSCOW TO URGE ON KHRUSHCHEV THE NEED FOR RUSSIAN INTERCESSION IN LAOS . " WE REGARD THE MAINTENANCE OF THE GENEVA ACCORDS AS ESSENTIAL TO THE SECURITY OF LAOS ITSELF, " SAID KENNEDY, " AND AS A TEST OF WHETHER IT IS POSSIBLE FOR AN ACCORD TO BE REACHED BETWEEN COUNTRIES WHICH HAVE SERIOUS DIFFERENCES . " IN MOSCOW, HARRIMAN WAS RECEIVED COOLLY ; ONLY A JUNIOR PROTOCOL OFFICER WAS AT THE AIRPORT TO MEET HIM . WHEN HE GOT TO THE KREMLIN, HE FOUND KHRUSHCHEV MORE THAN HAPPY TO GIVE VAGUE ENDORSEMENT OF THE GENEVA ACCORDS, BUT LESS THAN WILLING TO TAKE ANY CONCRETE ACTION TO STOP THE FIGHTING IN THE PLAIN OF JARS. THE ROAD BUILDERS . AS THE DIPLOMATS TALKED, THE PENTAGON WAS QUIETLY FLEXING ITS MUSCLES . UNITS OF THE U.S . SEVENTH FLEET BEGAN CRUISING IN THE SOUTH CHINA SEA, AND THOUGH THE MOVE HAD BEEN PLANNED FOR MONTHS, WASHINGTON PICKED LAST WEEK TO ANNOUNCE THAT TWO COMBAT-READY BATTLE GROUPS WOULD SOON MOVE INTO THAILAND TO TAKE PART IN NEXT MONTH'S FULL-SCALE SEATO BATTLE MANEUVERS . IT WAS REMINISCENT OF THE CRASH BUILDUP OF TROOP STRENGTH IN THAILAND JUST A YEAR AGO, WHEN THE LAST SERIOUS FLARE-UP IN LAOS TOOK PLACE . LEFT BEHIND WHEN THESE TROOPS WERE WITHDRAWN WERE ENOUGH TRUCKS, TANKS AND PERSONNEL CARRIERS TO EQUIP A THIRD BATTLE GROUP THAT MIGHT BE NEEDED IN THE EVENT OF EMERGENCY . THE PLAIN IS NAMED FOR THE SCORES OF LARGE, STONE BURIAL URNS DOTTING THE AREA, IN WHICH THE ANCESTRAL ASHES OF THE LAOTIAN PEOPLE WERE ONCE DEPOSITED . BOTH THE PATHET LAO AND THE NEUTRALISTS AVOID FIGHTING NEAR THE JARS, FOR LAOTIAN TRADITION HOLDS THAT THE PENALTY FOR DISTURBING THEM IS A VIOLENT AND FIERY RETRIBUTION FROM THE SPIRITS WITHIN . APART FROM THE COMBAT TROOPS, SOME 2,600 OTHER U.S . MILITARY PERSONNEL CHIEFLY ENGINEERS AND SIGNAL TROOPS ARE IN THAILAND . NEAR THE LAOTIAN BORDER, A U.S . ARMY CONSTRUCTION BATTALION IS NEARING COMPLETION OF AN ALLWEATHER JET AIRSTRIP . AT A MEETING WITH TOP U.S . AIDES IN BANGKOK, ADMIRAL HARRY D . FELT, COMMANDER OF ALL U.S . FORCES IN THE PACIFIC, DISCUSSED CONTINGENCY PLANS IN THE EVENT THAT THE PATHET LAO MOVES OFF THE PLAIN OF JARS INTO THE MEKONG RIVER VALLEY . THE U.S . IS NOT COMMITTED TO PUT TROOPS INTO LAOS, AND THE MILITARY IS NOT ENTHUSIASTIC ABOUT THE PROSPECT OF FIGHTING THERE, FOR THE LACK OF AIRFIELDS, RAILROADS AND GOOD ROADS WOULD MAKE IT TOUGH TO SUSTAIN OPERATIONS . BUT IF THE PATHET LAO SHOWED AN INCLINATION TO SWEEP ALL THE WAY SOUTH, THE U.S . FORCES IN THAILAND MIGHT WELL HAVE TO MOVE ACROSS THE MEKONG AND OCCUPY THE LAOTIAN CAPITAL OF VIENTIANE AND OTHER STRATEGIC POINTS IN THE VALLEY . MEANWHILE IN LAOS ITSELF, A LULL HAD SETTLED OVER THE BATTLEFIELD . IN A FLYING VISIT TO THE PLAIN OF JARS, NEUTRALIST PREMIER SOUVANNA PHOUMA MANAGED TO ARRANGE A SHAKY CEASE-FIRE BETWEEN THE PATHET LAO AND KONG LE'S NEUTRALISTS . THOUGH SPORADIC ARTILLERY DUELS STILL POCKMARKED THE PLAIN, THERE WERE NO OUTRIGHT RED ATTACKS, AND THE NEUTRALISTS LOST NO NEW TERRITORY . BUT HOSTILITIES THREATENED TO ERUPT FROM ANOTHER QUARTER . AROUND THE PERIMETER OF THE PLAIN, RIGHT-WING GENERAL PHOUMI NOSAVAN WAS REINFORCING HIS POSITIONS, AND IN THE FOOTHILLS BEHIND THE PATHET LAO LINES, TOUGH, WELL-ARMED MEO TRIBESMEN, WHO HAVE NO LOVE FOR THE REDS, POSED A DANGEROUS THREAT TO COMMUNIST SUPPLY ROUTES FROM NORTH VIET NAM . IF LAOS SHOULD FALL TO THE REDS, NORTH VIET NAM'S HO CHI MINH TRAIL (SEE MAP), THE SUPPLY ROUTE WHICH CUTS THROUGH THE LAOTIAN THICKETS TO COMMUNIST VIET CONG GUERRILLAS IN SOUTH VIET NAM, WOULD OPEN UP, PERMITTING THE REDS TO POUR ARMS AND MEN INTO THAT EMBATTLED LAND . CONTROL OF LAOS' MEKONG RIVER VALLEY WOULD ALSO GIVE THE COMMUNISTS A HIGHWAY FOR SUBVERSION OF NEIGHBORING CAMBODIA AND THAILAND, WHICH IN TURN WOULD INCREASE RED PRESSURE ON BURMA AND MALAYA . FAIT ACCOMPLI . FOR THE MOMENT, THE REDS APPEARED CONTENT TO CONSOLIDATE THEIR NEW TERRITORIAL GAINS ON THE PLAIN OF JARS AND TO LET THE CRISIS COOL OF ITS OWN ACCORD . IF THEY MOVED OFF THE PLAIN, THEY WOULD SURELY MARCH RIGHT INTO A CIVIL WAR WITH PHOUMI'S RIGHTIST FORCES, THUS INVITING U.S . INTERVENTION, WHICH THEY WISHED TO AVOID AT ALL COSTS . DESPITE PROTESTS BY BOTH SOUVANNA AND THE U.S., THE PATHET LAO'S TERRITORIAL GRAB WAS A FAIT ACCOMPLI . THERE WERE THOSE IN THE U.S . WHO THOUGHT THE ONLY LONG-RANGE ANSWER TO THE LAOS PROBLEM WAS OUTRIGHT PARTITION . ALREADY A DE FACTO PARTITION OF LAOS EXISTED : THE NORTHERN PART OF THE COUNTRY WAS FIRMLY CONTROLLED BY THE COMMUNISTS, AND THE RICE-RICH MEKONG RIVER VALLEY WAS IN THE HANDS OF THE RIGHTISTS . IT WAS NOT THE IDEAL SOLUTION FOR LAOS . BUT, AS ONE U.S . OFFICIAL SAID " THERE ARE NO GOOD SOLUTIONS IN LAOS . THERE NEVER WILL BE . LAOS HAS ALWAYS BEEN A LOSING PROPOSITION . /