MAURITANIA DADDAH KNOWS BEST WHEN MAURITANIA WON ITS INDEPENDENCE IN 1960, SOVEREIGNTY AND SAND WERE ABOUT ALL IT HAD . SPRAWLED ACROSS THE LOWER SAHARA ON AFRICA'S ATLANTIC HUMP, THE ARID NATION IS TWICE THE SIZE OF FRANCE BUT HAS ONLY 800,000 PEOPLE AND AN AVERAGE PER CAPITA INCOME OF LESS THAN $80 YEARLY . NONETHELESS SINCE 1956 MOROCCO HAS BEEN STRUGGLING TO ANNEX " THE STOLEN SANDS OF MAURITANIA, " WHICH IT CLAIMS WERE ILLEGALLY TAKEN FROM COLONIAL MOROCCO BY FRENCH ARMY SURVEYORS THE LATE KING MOHAMMED V, A " MOROCCAN LIBERATION ARMY " EVEN TRIED TO " FREE " MAURITANIA ; WITH SUPPORT FROM RUSSIA, MOROCCO MANAGED TO KEEP THE NEW NATION OUT OF THE U.N . FOR A WHOLE YEAR . DEFYING MOROCCO, MAURITANIA'S SORBONNE-EDUCATED PREMIER MOKTAR OULD DADDAH, 38, HAS ARGUED ALL ALONG THAT THERE IS NO HISTORICAL BASIS FOR UNION, AND THAT THE TWO COUNTRIES HAVE NEITHER LANGUAGE NOR ETHNIC ORIGINS IN COMMON . ONE BY ONE, THE FORMER FRENCH COLONIES THAT BACKED MOROCCO'S CLAIMS HAVE ALL DROPPED OUT OF THE BATTLE . ALGERIA'S MILITANT AHMED BEN BELLA ALLOWED RECENTLY THAT MAURITANIA'S NATIONHOOD IS A " REALITY . " LAST WEEK EVEN NEIGHBORING MALI, WHICH ALSO CLAIMED PART OF MAURITANIA AND PERMITTED PRO-MOROCCAN GUERRILLAS TO RAID THE DESERT NATION A YEAR AGO, FINALLY BURIED THE HATCHET . WITH ROYALTIES BEGINNING TO FLOW INTO HIS TREASURY FROM BIG, WESTERN-FINANCED IRON-ORE MINES, OULD DADDAH CUT OFF THE $4,000,000 ANNUAL SUBSIDY HIS GOVERNMENT HAS BEEN GETTING FROM FRANCE, THUS EFFECTIVELY ANSWERING AFRICAN TAUNTS THAT HE IS A " VALET OF THE FRENCH . " HOWEVER, EVEN THOUGH THERE TURNED OUT TO BE GOLD (AND IRON) IN MAURITANIA'S SANDS, IT HAS BECOME INCREASINGLY PLAIN THAT MOROCCO'S PRAGMATIC YOUNG KING HASSAN II DOES NOT SHARE HIS FATHER'S FERVENT FAITH IN A " GREATER MOROCCO " AND REALIZES, IN ANY CASE, THAT ITS BIG NEIGHBOR IS HERE TO STAY . MOREOVER, THE KING NOW HAS SUFFICIENT POLITICAL STRENGTH TO RESIST PRESSURE FROM THE NATIONALIST ISTIQLAL PARTY, MOST DOGGED ADVOCATE OF MAURITANIA'S ANNEXATION . LAST WEEK, HE DECIDED TO REPATRIATE FOUR PROMINENT MAURITANIAN EXILES WHO HAD BEEN LEADING THE CAMPAIGN AGAINST THEIR COUNTRY FROM MOROCCO FOR SEVERAL YEARS . IN MAY, WHEN AFRICA'S LEADERS MEET FOR A " SUMMIT " CONFERENCE AT ADDIS ABABA, HASSAN IS EXPECTED TO MAKE MOROCCO'S NEW POLICY OFFICIAL .