AMERICAN EMBASSY REBUILDS IN ISLAMABAD

At pool parties inside the smoke-blackened United States Embassy compound in Islamabad, diplomats sport T-shirts proclaiming "Veteran of the Vault" and "Pak Evac."

Six months after Pakistani mobs savaged the embassy in an attack that killed two Americans and two Pakistani employees, the American diplomatic community here is struggling to resume the motions of normal life.

But it is a lonely community of parents without children and husbands without wives in the Pakistan capital once, but no longer, known in diplomatic circles as "dull but safe." Most of the children splashing happily in the embassy pool against an eerie backdrop of gutted buildings are Canadian, British, and Australian. American children were evacuated two days after the Nov. 21 attack that trapped 137 persons for a time in the burning embassy. The children can't return, the State Department has ruled, until June 15.

Few wives have returned since the State Department allowed them back on May 15. "It can't ever be the same again," says one woman, back solely to help her husband pack up to leave this month. A husband grumbles that the meals turned out by his cook have deteriorated without the memsahibm on hand to supervise.

Pakistanis do not like to talk about the day that could have become America's most serious Foreign Service disaster. That their Army arrived hours late and watched idly as 137 persons came close to perishing in the vault of the burning embassy is a source of acute embarrassment. The murmurs of shame and regret are sincere, but the subject is quickly changed.

"It will not be conducive to a closer understanding with America to suddenly whip up this thing again," says Information Minister S. Shahid Hamid. "It may not be an appropriate thing."

Pakistan has offered to pay for rebuilding the embassy, as it must under international law. But embassy personnel complain they get no responses to queries on the status of cases and prosecutions of those arrested in the violence, believed to number 38. A prominent educator admonished one startled diplomat to remember that the attackers were "just exuberant kids."

The diplomat, a survivor of the five-hour ordeal in the embassy vault, did not find it an apt description. By official Pakistani estimates, the student-led demonstrators who first appeared at the embassy the day before Thanksgiving quickly swelled to a mob of 20,000. They carried guns, Molotov cocktails, steel bars, rocks, and bricks. They smashed through brick walls, metal shutters, grilles, and thick security doors to enter and burn the embassy and its outlying buildings on the 36-acre American compound.

Their fury was touched off by false rumors that Americans had been involved in an attack on the Grand Mosque in Mecca, one of Islam's holiest sites. Their government could not and would not stop them for fear that the mob would turn against it, most diplomatic observers believe and many Pakistanis privately acknowledge.

The "Veterans of the Vault" finally left on their own: With perhaps 15 minutes to spare as the smoke thickened and temperatures soared in the steel-lined room, they had no choice. Their relief at a dramatic escape over the fire-ringed roof and down ladders to the ground turned to fury of their own -- at both the Pakistani government's failure to help them and the Carter administration's thanks to Pakistan for a quick end to the embassy siege.

Almost immediately there were jobs to do. Dependents and nonessential personnel had to pack up for the stealthy pre-dawn evacuation. Clothing had to be found for embassy staffers left with nothing after the burning of their embassy compound apartments.

Offices were hastily relocated to a US Agency for International Development (AID) facility that was due to be closed. It remains what Islamabad taxi drivers call the "new" US Embassy, but security has been tightened.

Many of the American survivors -- Pakistani employees accounted for about half of those trapped inside the vault -- took quick advantage of a State Department offer of shortened tours and transfers elsewhere. Those remaining went home in two shifts to see their families on special Christmas and New Year leaves and came back to a new world crisis: Soviet troops in neighboring Afghanistan. In Washington and Islamabad, the issue of the embassy catastrophe faded in the initial rush to bolster Pakistan with military and economic aid.

At the "old" embassy, opened in 1973 at a cost of $21 million, a crew of 150 workers provided by the Pakistani government worked for a month to clear the debris.

A team of engineers from the State Department's foreign-buildings office came and pronounced the three-story embassy structurally sound but weakened, and recommended that partitions replace interior brick walls to lighten the load on the floors. On May 14, the State Department invited three firms to bid on the reconstruction. At this writing the bids had not yet been received.

Reopening the old embassy buildings is at least two years away. Meanwhile, the softball field, tennis courts, and swimming pool are back in business, and pink roses bloom in front of the windowless, burned out Marine guard quarters.

The staff roster, down to 62 after the evacuation, has crept up to 95. Between the normal summer embassy staff turnover and the liberal transfer policy , the number of American diplomats involved in the November afternoon of terror is dwindling fast. By summer's end only eight State Department employees, two US International Communication Agency personnel, and a handful of AID staff members will remain of the 120 here before the fire.