The IDF underperformed in the war, and quite a few of their
Merkava tanks were knocked out or disabled, and even a frigate got
hit (it had its electronic countermeasures switched off for some
damn reason) and had to be towed back. If by anything, the IDF did
not achieve any of their objectives, short of bombing the hell out
of South Lebanon.
The damage was inflicted from the air, on the ground, they got
ambushed, pushed back, and what not. It was in some of the western
papers, not sure if ST bothered to publish any of it. Even if the
Israelis went to Beirut, what would it have served? Politically,
you would have every Arab country against them. As it is, the
Hezbollah were able to hide their weapons, and struck the Israelis
pretty badly. I remember there was some article in the NYT that
said that only one unit performed well, whereas the other units did
not, and they were the reservist units by the way.
The Israelis aren't what they were decades ago. More reliant on
high tech weapons, and short on proper training. Couple that with
an intelligence failure of significant magnitude, you have a war
where the IDF achieved none of its objectives.