How worried the IDF is in reality is not always the same to how worried they are on the record. The IDF would say they are worried about the Syrian army getting catapults if they thought it would stop them getting anything because all armies like the enemy to be as weak as possible. Israel still has options assuming the IDF is as worried as it claims. They have satellittes & UAVS to fly into Syria undetected which can track where Syria stores these toys and take them out. It can try and find a friendly country who has the system and Israel can practice trying to beat it. Israel might do what it did in 1968 when it snuck into Egypt in the middle of the night dismantled and flew an advanced russian radar to Israel for study and then passed it onto the US so it can learn how to get around the things. Israel can upgrade its own defenses. Israel has always been willing to play dirty which makes it unpredictable in its tactics which gives it an edge. In 1956 when the British & French asked Israel to join a coalition in the Suez war is was more than willing to help because Egypt had just taken delivery of some advanced fighter jets and at the time Israel had no jets so its price was jets from France and it then used those jets to help destroy Egypts before the egyptian pilots learned how to use them to maximum effect. So Israel got its own jets free of charge and it got to destroy Egypts jets at the same time. If it came to war with Syria Israel could win it hands down with or without the P-800. Russia would probably welcome a war because it means when its all over Syria will need to buy more hardware to replace whats been lost.
from the article: Despite Israeli protests, Russia won't halt arms sale to Syria