JERUSALEM, JAN. 1 -- Over the last few days, Jordan's army has been implementing its "Al-Quds" mobilization plan, in which most of its 80,000 troops are deployed in the mountains overlooking the Jordan Valley and in other defensive positions facing Israel, according to official sources here and diplomats in Amman.

Israel's prime minister, Yitzhak Shamir, and military chief of staff, Lt. Gen. Dan Shomron, have both issued statements assuring Jordan that it has nothing to fear from Israel, which has pledged to stay out of the Persian Gulf crisis unless attacked by Iraq.

Nevertheless, officials here said, Jordan's deployment under "Al-Quds," the Arabic word for Jerusalem, is continuing into its advanced phases. By the end of the week, the Israelis said, King Hussein's army will be fully positioned according to its plan for meeting an attack from Israel.

"What is the king doing?" a military official here asked, a note of suspicion in his voice. "We don't feel threatened by the deployment, because it is defensive. But we see the other side putting on their helmets, and we don't know why. Does the king really think Israel is going to attack? Or does he know something about the intentions of {Iraqi President} Saddam Hussein that we don't?"

In fact, Jordan's deployment appears to analysts here to be just one more move in what has become a complex game of alerts, tests, hints and feints among the multiple armies now gathered in the Middle East. As the Persian Gulf crisis teeters closer to war, Israel, Jordan and several other countries on the fringe are engaged in a battle of nerves with Iraq as well as with each other, providing a potential trigger for an armed conflict no one may intend.

The concern is evident in Jordan, where officials are keeping their fingers crossed that a negotiated settlement will avoid war but at the same time are taking precautions, Washington Post correspondent Caryle Murphy reported from Amman. Diplomats there said Jordan's deployment of an undisclosed number of tanks and troops closer to the border is meant as a clear signal to Israel.

"We are not going to be a sitting duck," one senior Jordanian official said. "If the Iraqis feel they are going to strike against Israel, we'll stop that. Or if Israel wants to cross our territory, we'll stop that, too."

"I'm surprised that a war by accident hasn't happened already," said Gerald Steinberg, a specialist on Israeli defense policy who lectures at Tel Aviv's Bar Illan University. "Given the level of tension and the chances of mixed signals, I'm surprised at the restraint that's been shown, by the United States and by Israel as well."

Israel's strategists were rattled last month when Iraq test-fired one of its Al-Husseini intermediate-range missiles toward Israel. The missile landed in the Iraqi desert. But Israeli sources say U.S. surveillance detected the launch only after the missile had been in the air for several minutes, then failed to warn Israel that a warhead was headed in its direction. The Israelis say this raised questions about what would happen if Saddam actually acted on his threat to fire missiles at Tel Aviv.

Since then, Israel has launched one of its own Jericho intermediate-range missiles over the Mediterranean, causing U.S. forces in Saudi Arabia to go on alert briefly. Iraq has fired at least two more missiles inside its territory. Israel has invited photographers to record the Hawk antiaircraft missile batteries it has deployed in the mountains of the West Bank. And now Jordan is deploying its army across the border on the opposite ridge.

"What is happening is that the various parties involved here are trying to prove to each other that they are serious, that they are capable of fighting a war if necessary," a senior Israeli official said. "No one wants a war. What is happening is that every country, including Iraq, is trying to ward off an attack. The question is whether the signals are understood, and that's something you can't know for sure."

Israelis are spending a lot of time debating the meaning of the signals they are perceiving from Iraq and Jordan. While some say the deployments and missile tests are merely signs that both countries are anxious to head off a regional conflict, others see them as ominous portents of a war in which Israel seems likely to become involved.

Iraq's missile firings, officials here said, may be little more than noisy demonstrations, designed to reinforce American fears that a U.S. attack on Iraqi forces in Kuwait could lead to heavy U.S. casualties. But analyst Steinberg said they could also be intended to give Saddam maneuvering room in case he does decide to launch a massive missile strike on Israel or Saudi Arabia.

"The Iraqis may be trying to find out to what degree they can fire missiles inside Iraq without triggering an immediate response from the United States or Israel," Steinberg said. "Now, if they get everyone used to it, maybe one day they will be able to turn around and get away with a real attack."

Whatever their purpose, the missile firings have had the effect of testing -- and possibly improving -- cooperation between Israel and the United States, officials here said. For some time, Israeli officials have hoped that if Iraq decided to shoot missiles at Israel, U.S. satellite surveillance would detect them even before they were launched, giving Israel an opportunity to preempt the strike.

In that sense, said Zeev Schiff, a senior defense correspondent for the Haaretz newspaper, "for the Israelis, the Iraqi test is also a test of how much the Americans know." In the first firing, sources said, U.S. notification came so late that Israeli officials complained to William Brown, the U.S. ambassador in Tel Aviv. By the time of the last launching, however, cooperation had improved and "we were given almost everything we needed to know at the time we needed to know it," a senior official said.

Official sources insisted that Israel's own test firing of a Jericho missile 10 days ago was planned long before the present crisis. "But I suppose that by not canceling a test that was already planned, we were also sending a message," one source said. "We want it to be clear to Saddam and to everyone that we are ready to respond to any attack."

In the case of the Jordanian army deployment, Israeli analysts said misperceptions as well as strategy might be driving events. "For many years the Jordanians have feared that Israel has ideas about turning Jordan into a Palestinian state. And perhaps now in the Jordanian leadership there are those who fear that Israel may intend to use the gulf crisis to accomplish that," said Asher Susser, a specialist on Jordan at the Dayan Center of Tel Aviv University.

Other Israelis say King Hussein might be worried about the possibility that an Iraqi attack on Israel will prompt Israel to mount an air strike on Iraq, using Jordanian air space on their way to their targets. That would present Hussein with the choice he faced in 1967 and 1973: whether to intervene in a fight between Israel and another Arab power.

How Jordan would respond to a violation of its airspace, which some diplomats in Amman see more likely than a ground incursion, is unclear. Although Jordanian officials say they intend to respond to any violation of their sovereignty, Jordan's small air force is no match for either Israel's or Iraq's.

One Jordanian official suggested that Iraq-bound Israeli warplanes might avoid Jordanian airspace by flying over Saudi Arabia, Murphy reported from Amman. The official said this is the route Israel used in 1981 when its planes bombed and destroyed Iraq's nuclear reactor.

Jordan's deployment to forward defensive positions was done with no effort to hide it, in order not to provoke Israel, a diplomat in Amman said. But it was intended to show, as much for domestic reasons as any other, that Jordan will respond to any attempt by Israel during a conflict to take Jordanian territory, diplomats and Jordanians said.

A senior Jordanian official said he does not regard an Israeli incursion as likely, and the Jordanian press published Shomron's recent statement that Jordanians "are mistaken in their estimation that we have intentions to invade Jordan, to harm it, to occupy territory. We do not have such intentions."

Still, many Jordanians say they fear Israel might respond to an Iraqi provocation by invading Jordan, a view shared by some diplomats in Amman.

A senior Israeli official said that if the Jordanian deployment is Hussein's way of signaling that he will resist any move by Israel to attack Iraq through Jordanian territory, Israeli officials have a blunt message to send back.

"We don't have any intention to harm the king," the official said, "but here is a message for him: if he tries to intervene between us and Iraq, it could lead to a 5th of June revisited." On June 5, 1967, Jordan entered the Six-Day War, leading to its loss to Israel of East Jerusalem and the West Bank.