Israel Edgy as Violence Flares Up : Tension: Meanwhile, the government mounts a campaign to get the country back to normal.

Reverberations from the Persian Gulf War have the effect in Israel of a kind of low-grade fever, something not yet fully debilitating but always in danger of flaring into something worse.

Within the last day, there were a number of incidents that reminded the country of the risks that confront Israel as the war drags on: a border infiltration, a violent incident in East Jerusalem and still another missile attack from western Iraq.

Three infiltrators from Jordan crossed the border near Beer Menuhah in the far south Friday and threw hand grenades at a bus carrying soldiers. A roving patrol chased the gunmen and shot them to death near a hastily erected roadblock. Four Israeli soldiers were slightly wounded in the grenade attack, military spokesmen said.

The cross-border attack highlighted often-expressed concerns that Jordan’s King Hussein may lose control of his armed forces and population and a war might break out that neither Jordan nor Israel seems to want.

Jordan is technically neutral--a point the United States now disputes. Jordan’s majority Palestinian population largely backs Iraqi leader Saddam Hussein in his war with the U.S.-led multinational force.

Israeli officials advised that Jordan’s army is trying to prevent raids into Israel. But Israel’s defense minister, Moshe Arens, commented dryly on radio, “They’re not trying hard enough.”

In Arab-populated East Jerusalem on Friday, a Palestinian attacked a post office guard with an ax. The guard was lightly wounded and shot the Palestinian in the buttocks. A companion of the wounded Palestinian escaped but was captured later. Like those in Jordan, most of the Palestinians under Israeli rule roundly support Iraq.

The stabbing took place as the Israeli government announced plans to permit Palestinian laborers back into Israel where they are needed in construction and the harvest of winter crops. Palestinian households in the occupied West Bank and Gaza Strip are suffering under the effects of a long curfew that is drying up cash among the idle population.

Israeli military officials have confined the 1.7 million residents of the occupied territories to their homes for most of three weeks in order to head off pro-Iraq turbulence. The government warned that a resurgence of unrest could derail plans to lift the curfew and the ban on travel into Israel.

Finally, in the early hours today, Iraq launched its 11th aerial attack against Israel. One Scud ballistic missile was launched from western Iraq and fell in the greater Tel Aviv area, leaving a six-foot-wide crater in the middle of a residential street. Army spokesmen said that at least 20 people were injured, none seriously.

Until this morning, no missile had hit Israeli-held land since last Sunday, and none had done substantial damage for more than two weeks.

Military spokesmen say that the Iraqis have been forced to move their missiles around on mobile launchers, putting them in places where their erratic aim is even less reliable. Despite the continuing efforts of allied bombers to knock out the sites in western Iraq, the Baghdad regime is estimated to still possess about 30 launchers and scores of missiles.

Still, the Israeli government has mounted a campaign to get the country back to normal and citizens back to their jobs. Movie houses and nightclubs are being allowed to reopen, but they are permitted to operate only at half capacity to avoid overcrowding and panic in case an air raid siren sounds.

Attention shifted to Jordan in the wake of King Hussein’s speech Wednesday condemning the war and expressing support for the people of Iraq. Washington has interpreted the speech as meaning that the king is now fully siding with Iraq in the conflict.

Israeli Prime Minister Yitzhak Shamir remarked that “Hussein’s speech worries us because, after all, he’s our neighbor, and everything that happens there influences what’s happening here.

“We are paying attention to it, drawing conclusions,” Shamir added, “and I hope that both Jordan and we will pass this situation safely.”

Watching the Jordanian king’s moves and moods has become a national sport among Israeli officials and expert commentators. When the king grew a beard recently, officials wondered whether he was losing his mind. When he disappears from public for any length of time, they wonder if he has been overthrown.

“Probably, there has never been a time when so many people were worried about the king’s well-being,” said Asher Susser, an expert on Jordan.

Israel has contributed to international pressure on Hussein by seconding charges made in Washington that, despite the international embargo on Iraq, Jordan is actively aiding Iraq’s war effort. When officials in Washington charged that Jordanians were hiding missile parts in oil tanker trucks--making the vehicles legitimate target for attack--Israeli officials suggested that the parts were going to be used to construct a more powerful missile to strike at Israel.

Tension is high along the Jordanian frontier, and one other cross-border raid took place early in the Iraq war. A Palestinian in Jordan’s army shot at an Israeli soldier on patrol, who was lightly wounded.

Despite the problems, Israeli officials insist that Jordan is being careful not to provoke Israel. Jordanian troops on the ridges above the Jordan Valley are being kept in defensive and immobile positions. Quiet contact between the two governments is maintained to ensure that no incident explodes into combat.

At night, one military official said, Jordanians openly light up cigarettes, a breach of security that is meant to show that they have no aggressive intentions.

In Lebanon earlier in the week, Israeli ground troops assaulted a base used by the Fatah faction of the Palestine Liberation Organization. Fatah is directly headed by PLO chief Yasser Arafat. Israel insists that Fatah is responsible for firing rockets into a buffer zone created by Israel in Lebanon and patrolled by both Israeli troops and a client Lebanese militia.

The attack on the Fatah base took place well north of the zone, near the city of Sidon. Israeli troops and attack helicopters destroyed buildings and tents belonging to the guerrillas. Artillery exchanges and air attacks have taken place throughout the week in southern Lebanon.

The Israeli government maintains that both the PLO and Lebanese guerrillas are trying to open a battle front on behalf of Saddam Hussein.