Remind me, why did Israel invade Gaza?

Any takers? Why was it? Regime change? Fight Hamas to the finish? To get Livni into power? Stop BiBi? I know what I'll do, I'll check out Ha'aretz, that's what I'll do. Hold on, let me have one more guess. It was to stop the rockets:

Three rockets fell Thursday in the area around the Gaza Strip, one in the yard of a Sderot home - just a few reminders that Israel is still far from its declared goal in Operation Cast Lead. Discussion about the military operation's outcome revolves around the term "deterrence."

Hmm, didn't stop the rockets then. How about regime change?

The blow Hamas was dealt has only led to increased admiration for the group, according to opinion polls in the territories. Hamas is still waiting for another crowning achievement: if abducted IDF soldier Gilad Shalit is released for more than 1,000 Palestinian prisoners.

Still it's not all doom and gloom for the racist war criminals:

However, the army is currently reviewing its performance during the war and an encouraging picture is emerging in terms of its professionalism, control over units, aerial assistance to ground forces, quality of intelligence and logistics compared to the Second Lebanon War.

In other words they clearly lost in Lebanon and almost lost in Gaza and time may have them lose in Gaza for sure.

The lesson? I don't know, any takers?