How about this: If Syria and Lebanon (Hezbollah) attack Israel in retaliation against an pre-emptive Israeli strike on Iranian nuclear facilities, then so be it. A full, robust response from Israel is totally reasonable and right. And if Arabs choose to target population centers, then Israel should have the right to capture/annex new lands in compensation. There must be consequences for obvious targeting of civilians. Don't target civilians (does not include military targets within civilian areas), and no need to worry about losing kilometer after kilometer. For example, launching rockets like Hezbollah did in the last war would be grounds for losing lands.
U.S., allies stage 20 strikes against Islamic State in Iraq (Reuters)
from the article: Report: Iran and Syria sign defense cooperation pact