THEY were passing out the gas masks again in Jerusalem last week.
Like some apocalyptic Groundhog Day it was an eerie re-run of those times back in January 1991 when the countdown to war with Iraq got under way and Israel braced itself for the worst.
As a correspondent based in Jerusalem then I well remember the days being crossed off on the "Saddam calendar" in my local cafe in the west of the city, confirming hostilities with Iraq were just hours away. Across Israel, the talk was of "defensive capability", "retaliatory strikes" and: "What if Iraq's Scud missiles get through?"
On Jerusalem's Ben Yehuda Street I recall two young Israelis running a stall. In best barrow-boy tradition, they called out the indispensable qualities of the items on sale. "Heavy duty, three shekel per metre. Lightweight, one shekel!"
One of them held up the plastic sheet, while the other dished out rolls of sticky tape from a stack piled up on a table in front of him.
"The complete do-it-yourself home protection kit against a gas attack," he assured me, pausing for a moment before adding with a telling shrug, "along with your personal gas mask, of course."
Waiting for the Gulf War to begin in 1991 in Jerusalem was a serious business. It is no less so today as the drum-beat of war between Israel and Iran reaches a crescendo.
Over the last few weeks the country has been testing a new text-messaging system for alerting Israelis to incoming rockets. Some citizens have returned home at the end of the working day to find official reminder letters asking if they have enough gas masks for the whole family.
The Israeli press is full of alarming stories such as whether there are sufficient bomb shelters in major cities. And, just like in 1991, there are reports that some Israelis have been queuing to get passports in case they want to leave in a hurry.
But will it really come to that, and, if it does, what can Israel, Iran and the world expect to happen?
Last week a US blogger published what he claimed were Israel's war plans leaked by an Israeli army officer. The document promises "an unprecedented cyber-attack", a "barrage" of cruise missiles "to completely decapitate Iran's professional and command ranks" followed by an attack by planes with special equipment to render them invisible.
Compelling doubts have been raised about the veracity of the document. A similar document appeared days earlier on an Israeli internet forum that said it was based on "Israeli publications, foreign media reports and the author's own imagination".
Israelis are fond of recounting their country's military exploits, not least audacious ones such as Operation Opera, the 1981 Israeli air strike that destroyed an Iraqi nuclear reactor under construction near Baghdad.
Many military analysts see that operation – controversial as it was – as being the one that effectively thwarted Saddam Hussein's ambitions to obtain weapons of mass destruction, and one of the most successful preventive attacks in modern history. Given this, it's hardly surprising many within the Israeli establishment see it as the template for halting Iran's nuclear weapons.
But should events move in that direction the chances of outright success are doubtful. Indeed some analysts believe Israel's air force lacks the capability to destroy Iran's nuclear installations.
Firstly, there are logistical problems, in that war with Iran would require Israel's 125 F-151 and F-161 aircraft to hit targets up to 1200 miles from home, which would require complex in-flight refuelling. Then there is the question of whether the planes' armaments payload is powerful enough to penetrate the likes of Iran's uranium enrichment plant at Fordow which is embedded in a mountain, protected by hundreds of feet of rock and earth.
A report this month based on satellite surveillance by the Washington-based Institute for Science and International Security says Tehran has strengthened the Fordow plant, reinforcing its entrances and ventilation shafts.
Israel of course has never claimed its airforce could wipe out Iran's distant, numerous and well-fortified facilities. Some officials prefer to argue instead that buying time would be a good enough result.
"If we succeed in pushing off the nuclear programme by six or eight or 10 years, there's a good chance that the [Iranian] regime will not survive," an unidentified top "decision maker", widely believed to be defence minister Ehud Barak, told Haaretz newspaper last Friday. He added: "The objective is delay."
Should it come to all-out war, however, there would of course be Iranian retaliation to Israeli strikes. Few doubt a missile war would ensue, with Israel facing a barrage from Iran's growing ballistic arsenal.
At the spearhead of such an onslaught would be the Shahab-3 missile, which analysis prepared by the Centre for Strategic and International Studies (CSIS) says can fly up to 1300 kilometers and carry a high-explosive or chemical warhead weighing up to 1100 kilograms. Iran could have as many as 100 of these dug into underground silos and mounted on truck launchers.
Only last week Matan Vilnai, Israel's outgoing civil defence minister, said Israel estimates a war with Iran would last a month, and the country could expect hundreds of missile hits daily, which could kill 500 people by the end of the war.
But Iran has other ways too of hitting back. It might use its Hezbollah militia allies in neighbouring Lebanon to rain down smaller missiles, as happened during Hezbollah's 2006 war with Israel.
Tehran might also want to make the wider world hurt by trying to close the Straits of Hormuz on its southern coast, through which 40% of the world's oil shipments pass. As the speculation, spin, leaks and anonymous briefings continue, so too does the anxiety.
"All this exceeds anything I have ever seen before, and I have been around a long time," said Uri Dromi, a spokesman for former Prime Minister Yitzhak Rabin, who accused current Israeli Prime Minister, Benjamin Netanyahu of reckless scaremongering and damaging ties with Washington.
"It seems like he has forgotten who is the super power here," insisted Dromi.
While Vilnai might claim any Israel-Iran war would taper off within a month, the impact of an all-out conflict on the region and world for years to come would be profound.
If hostilities start, who knows where they might end. While Israel has always maintained a policy of "nuclear ambiguity", never officially admitting having a nuclear arsenal, it is widely believed have one.
In 1991, at the height of Iraq's Scud missile attacks on Israeli cities, I remember during a press conference the chilling response of an Israeli Defence Force spokesman when asked what Israel's response might be if one of Saddam's missiles contained, say, sarin or another chemical or biological agent.
"We would turn Baghdad into a sheet of glass," came the spokesman's immediate reply. It was a frightening moment. No conferring, no hesitation, just an implied nuclear strike. At the time, he left no-one in any doubt that he meant what he said. But, then, when it comes to its own security, Israel usually does mean what it says.