Disappointed with the delay in the U.S. decision to launch a strike against the Syrian regime, Israel is bracing for possible consequences. The Israel Air Force (IAF) was placed on high alert, took delivery of a sixth counter-rocket Iron Dome system and is preparing to deploy a seventh.

“Israelis should carry on with their daily routine,” declared Prime Minister Benjamin Netanyahu, but at the same time he allowed the Israel Defense Forces (IDF) to draft an additional 1,000 reserve servicemen, mostly from the Air Defense Corps.

The IAF took delivery of a sixth Iron Dome battery from Rafael and deployed the entire arsenal in Northern, Central and Southern Israel. A seventh battery is expected to be ready for deployment by the time the U.S. is prepared to strike. The Arrow 2 anti-ballistic missile system was also placed on high alert as well as the Patriot MIM-104 surface-to-air missile batteries.

Syrian President Bashar al-Assad has already used half of Syria’s arsenal of Scud missiles in the civil war, but he is believed to still possess a stockpile of 500 Scud B/C/Ds, with ranges of 300, 500 and 700 km, respectively. But while the liquid-propellant Scuds require long refueling time, which exposes them before launch to potential strike, Israel is more concerned about the Syrian army’s vast stockpile of solid-fuel M600 missiles. A clone of the Iranian Fateh-110 missile, the Syrian-made M600 can carry a 500-kg warhead to a range of 300 km, covering all of Israel’s population centers and strategic sites. Those, as well as tens of thousands of 302mm rockets with a range of 150 km, are all capable of carrying chemical warheads.

The Arrow system was originally designed to counter Scud missiles; the Iron Dome to counter short-range rockets. The middle-tier system – David’s Sling (aka Magic Wand) — which is supposed to deal with medium-range missiles like the M600, is still under development. Israel’s Patriot PAC-2s were deployed to fill in this gap until David’s Sling achieves initial operational capabilities. “We do have some capabilities in countering ballistic threats,” Lt. Col. Amir (whose last name is classified), commander of a Patriot battalion, told Aviation Week.

Despite its constantly declining capabilities, Israel still considers the Syrian air force a viable threat. At Ramat David Air Force Base in northern Israel, sirens go off every 2 hr. and fighters are sent scrambling, signaling that a Syrian fighter has taken a course toward the Israel border. “The last thing we should do is to underestimate the enemy,” said Lt. Col. G., commander of an F-16C/D squadron in Ramat David. “We don’t trust luck or coincidence. If there’s an aircraft flying towards Israel, we will be there to make sure it will not enter our airspace.”

In its last encounters with the Syrian air force between 1982 and 1986, the IAF scored in 100% of its engagements. Still, says Lt. Col. Assaf, commander of the IAF air control unit, “We monitor every action of them and take extra precautions, especially in times like this. They still fly. They’re operational, and we take them seriously.”

When Syria began receiving advanced Russian air defense systems in recent years, like the SA-17 (Grizzly/Buk) and the SA- 22 (Greyhound/Pantsyr), the IAF appeared concerned. After reports on seven different strikes the IAF conducted in Syria in 2013, those systems no longer pose a challenge to the IAF. That is why Israeli intelligence and decision makers confidently believe that Assad would not dare to challenge Israel.

“Assad knows that Israel could swiftly deny him of everything he still has,” a senior Israeli defense source told Aviation Week. “He should be suicidal to try anything against us, and he’s not.” Yet, the IDF simulated scenarios in the last two weeks with proxy organizations launching rocket strikes against Israel from Syria or Lebanon as a response to a U.S. strike.

“We will respond and respond harshly,” Netanyahu warned repeatedly.

Israeli leaders are ambiguous about whether the U.S. should strike Syria. On the one hand, they want the U.S. to decisively enforce the “red line” it declared over the use of chemical weapons. On the other hand, they don’t want to see an intervention in Syria, which could change the course of the civil war. Israeli leaders consider Assad a bitter enemy, but looking at the Syrian opposition, they fear the alternatives could be worse.

As Israel prepares to celebrate the Jewish high holidays in September, Israelis seeking to obtain gas masks lined up outside HomeFront Command distribution stations. Fearing that a U.S. strike could provoke Assad to launch a chemical attack on Israel, many civilians were rushing to receive a personal protection kit, provided by the military, with a gas mask and an atropine syringe protecting against nerve gas.

Repeated calming messages from the country’s leaders did not soothe the public’s anxiety. Many Israelis fear that if Assad was not deterred from using chemical weapons against his own people, he might try to use them against Israel as well.