Israel hopes a U.S. war on Iraq will eliminate one of its sworn enemies and chasten others -- but the cost could be very high if Saddam Hussein attacks the Jewish state with biological or chemical weapons, or his friends use the occasion to strike it on other fronts.
Israelis are eager to see the ouster of Saddam, who in 1991 hurled 39 Scud missiles at them in an effort to draw Israel into the war and drive a wedge between the United States and its Arab allies; Israel held back, and some say its prized deterrence was hobbled as a result.
Israel believes Iraq today has biological and chemical weapons, but there are many unknowns including whether it can mount them on missiles, whether Saddam would issue such an order, and whether it would be obeyed. There is also the possibility of a non-conventional bomb delivered by a plane or other means.
Prime Minister Ariel Sharon and other leaders warn Israel will defend its citizens if attacked -- but a desperate Saddam would be difficult to deter if his very aim is to draw a counterattack to redefine the war and enable his regime, somehow, to survive.
Hundreds of U.S. soldiers are to arrive in Israel this week for joint exercises to integrate two different anti-missile systems that are part of final preparations for a possible Iraqi attack. Israeli soldiers also have reportedly been training with chemical agents, learning how to detect them to warn the public in case of an attack.
If Israel is hit, its decision on how to respond could be gut-wrenching.
Sharon, in almost two years in power, has shown a great sensitivity to the position of the United States, whose support has been critical in his struggle to crush the Palestinian uprising and sideline Yasser Arafat. U.S. pressure on Israel not to respond, or to use measured force, would certainly be a factor.
Israeli security officials say that since a nonconventional attack would expose the falsehood of Iraq's claims that it does not possess such weapons, Israel must also plan for the scenario of an attack with conventional weapons.
But many believe that even in such a case Israel will have to act in order to to preserve -- or reestablish -- its deterrence.
Shmuel Sandler of the Tel Aviv-based BESA Center for Strategic Studies said the deterrent capability -- which for decades helped Israel stave off the hostile intentions of an Arab world whose population is many times its own -- has been battered by two decades "in which Israel failed to win decisively on any front."
The list includes -- in addition to the non-response to Saddam's Scuds in 1991 -- an 18-year occupation of parts of Lebanon that ended in a unilateral and unconditional pullout in 2000; the first Palestinian uprising that led to a since-collapsed peace deal with the Palestinian Liberation Organization in 1993; and the slow bleed of the current conflict with the Palestinians.
Few believe Israel would avoid retaliating to a biological or chemical attack that causes many casualties -- but no one can say how it would strike back.
Israel is reputed to have a significant nuclear capability -- but what kind of attack, with how many casualties, would justify using it? Beyond the unimaginable loss of innocent life, such an attack would break a taboo, expose Israel's nuclear hand and possibly invite similarly catastrophic retaliation.
For Israel to consider nuclear weapons, "it needs to be a very extreme situation (in which) there will a biological strike of such magnitude that Israel will have to respond," said Ephraim Kam of the Tel Aviv-based Jaffee Center for Strategic Studies. Israel said it would decide in the coming days whether to inoculate the entire population against smallpox. The Health Ministry has already inoculated between 15,000 and 20,000 medical and rescue workers against the virus.
The experts say it is in Israel's interest to avoid being challenged to respond.
That means relying on the United States to quickly seize control of western Iraq, the only place from which Iraqi Scuds can reach Israel, depending on the new Arrow missile defense system to knock down anything that does get through -- and, essentially, hoping for the best.
Another danger Israel could face is an upsurge in Palestinian terrorism or an effort by the Iranian-backed Hezbollah militia in Lebanon to broaden the war by attacking Israel with missiles.
Of particular are the oil refineries in the northern port of Haifa, well within Hezbollah's range. An attack that hits them and spews poison all over the area, where a half-million people live, is one of the "mega-terror" scenarios Israelis dread.
Israeli military planners are looking into ways to eliminate that threat, a goal that would require not only an air and artillery assault against Hezbollah's positions but also a ground move, and the risk of drawing in Syria, which effectively controls Lebanon, as well.
Israeli Defense Minister Shaul Mofaz said Dec. 16 that, "if Hezbollah opens a second front against Israel by using long-range rockets against the northern part of the state of Israel we won't have much choice."
Would the removal of Saddam herald a new era of moderation in the region?
Kam said it might embolden moderates and persuade hardline regimes from Teheran to Damascus to stop funding and providing shelter to terror groups.
"It would send a clear signal to the radical elements ... that the United States is ready to use force to ensure its interests against those who threaten stability," he said.
But others warn of a political and terrorist backlash against what could be perceived as new effort at Western colonialism.
And "the worse scenario is that the Americans are not successful, and the whole Middle East takes up arms against them -- and Israel," said Sandler.