Israel is formally at war with Lebanon and Syria so any flyovers are fully legal by 'international law'. They should just be greatful that they dont destroy every non-civilian target in both countries until they agree to peace now. These missiles are not going to change anything but they do point out the sad status of russia and syria.
Shaffir to Herzog: Opposition failed to show leadership in political battles against PM (Haaretz)
from the article: Sharon: Russian missiles being sold to Syria do threaten Israel