If you would only realize two things: 1) The vast majority of Beirut is still standing. Israel has mainly targeted the Hezbollah stronghold in the suburbs, and recently some targets in the northern end of the city. You are being fooled by pictures of collapsed buildings, which only represent a small minority of southern Lebanon. You should verify this yourself instead of relying on misleading media reports. I dare you. 2) If Israel wanted to "bring as much pain and devastation on Lebanon as possible", as you say, there would be many, many thousands of dead Lebanese, not just a few hundred.
Egypt postpones verdict in retrial of Al Jazeera journalists to Aug. 29 (Reuters)
from the article: Cabinet to meet over expansion of ground operations