For the first time since 2011, when the Iron Dome anti-rocket defense system became operational, it succeeded in intercepting two long-distance mortar shells over the Golan Heights on Saturday afternoon. Until now, all its interceptions were on the southern front – rockets fired from the Gaza Strip and Sinai.According to the IDF, the two rockets launched from Syria are considered “spillover” from the fierce battles between Assad’s army and the rebel groups not far from the Israeli border. The IDF estimates that it wasn’t intentional fire, but according to its policy intends to retaliate.Yesterday’s interceptions proved what has been already tested in the South and known to all experts – the Iron Dome is a good anti-rocket defense system, is innovative and has a high rate of success, but it also has its limits. It can’t “kill” rockets which fly for less than 25 seconds and are launched within a range of 5-6 kilometers.These scientific and technological handicaps are the Iron Dome’s metaphorical soft belly.IDF sources estimate that the two shells were fired from a distance of at least 7-8 km. from the border and belong to the heavy type of 120mm. mortars.Israel has 10 Iron Dome batteries, mostly financed by US congressional grants. But for full coverage of Israel’s skies, the IDF needs at least 14 batteries. Still, it would be a huge mistake to draw conclusions from the southern, and now northern, interceptions about future wars, especially with Hezbollah in Lebanon. As Israel runs its largest Home Front Command drill this week to prepare the population for any war eventuality, it is estimated by Israeli intelligence that Israel will have to deal with a barrage of some 1,500 missiles daily.Neither Iron Dome, which can kill up to a range of 70 km., nor the David Sling’s defense system, capable of intercepting missiles of up to 200 km., will be able to provide Israel with an airtight defense, although it’s important to add that Israeli intelligence doesn’t estimate that a war with Hezbollah or Syria is on the horizon. On the contrary, it is estimated that not Hezbollah nor Assad nor Hamas want to go to war with Israel.Regardless of who was behind the shells intercepted yesterday, official Israeli policy is to hold the Assad regime responsible for its territory and enforce its sovereignty.What really worries Israel, more than the random shelling from Syria, is the intensity of these events, as it was the sixth incident of this kind in the past two weeks. In every instance, Israel was forced to retaliate by artillery or fighter planes against Assad’s forces, which are stationed near the border.In one rare and unexpected case, the Syrian army fired two missiles at Israeli planes and missed. This chain of incidents lends to the concern that maybe the “unintentional” fire is actually intentional, with the ultimate goal of changing the rules of the game between Israel and the regime. So far, except for the aforementioned incident, the Syrian army has never responded to Israeli retaliatory attacks.Israel had previously sent strong warnings, via the coordination channels with Russia, that it won’t tolerate any change in the border equation.Prime Minister Benjamin Netanyahu called Russian President Vladimir Putin on Friday and asked him to make Israel’s feelings clear to Assad.