FOR 38 YEARS, Hassan II was a constitutional king of Morocco. He wrote the constitution, but it did not constrain his autocratic impulses. Common sense, shrewdness and a deft political touch did.

On balance, he was a force for good. Like his contemporary, King Hussein of Jordan who died in February, King Hassan thwarted assassination schemes, rolled with the punches and knew when to make concessions.

His death Friday at age 70 ended a period of progress and stability in his country of 29 million people. The rule of his 36-year-old son, King Mohammed VI, began immediately. Like his father, the new king has a French and Islamic Arab education and a reputation as a playboy and a democrat.

King Mohammed resembles the new King Abdullah of Jordan.

Both are heirs to pragmatic moderates. Both represent profound generational change while professing continuity. Both face dangers from within as well as from outside their nations.

King Hassan benefited from the legitimacy of a sultanate going back centuries. Although other Islamic monarchs have been secularists, he made himself the protector of Islam and builder of mosques. When last year's election went leftist, he made a formerly jailed opposition leader his prime minister, while imposing a loyalist hawk as interior minister.

King Hassan was justly valued by the West for stability and for brokering peace between Israel and its Arab neighbors. That tradition was maintained at his funeral, where Israel's Prime Minister Ehud Ba- rak met Arab rulers.

Some of King Hassan's opponents early on met death in mysterious ways, some while plotting his. But King Hassan's rule was benign compared with the Islamic extremist revolution in Algeria, the tyranny in Iraq and Syria and Libya, or the closed society of Saudi Arabia.

King Mohammed is said to want to curtail his powers while preserving his role on the model of the Spanish constitutional monarchy. He will need all his father's wily skills to achieve and survive that.