Syria means to have the Golan back and Israel knows this. Syria would be foolish to make an uncoordinated attack upon Israel and Israel knows this. Syria does have a "mutual defense" treaty with Iran. If there is an Israeli attack upon Iran, then Syria and Hizbollah will join the battle. If that war comes to pass, then Israel will certainly feel the pain like no war has ever brought home before. Israel should be concerned about a war with Syria, but it is not going to come from a solo Syrian attack upon Israel.
Gunmen in Egypt kill guard outside Niger embassy (Reuters)
from the article: Solana: There is no potential for war between Israel and Syria