The first day of Operation Pillar of Defense was quite successful. The Hamas military chief was assassinated and Hamas' long-range rocket capability was impaired, sending the radical Palestinian group into shock. The second day went pretty well too: Iron Dome proved its worth, Israeli civilians proved their steadfastness and Israel showed that it still enjoys a fair amount of international legitimacy and domestic cohesion.

Israeli unity, American support, European understanding, Turkish silence and Egyptian cooperation: All put Israel in quite a good strategic position on Friday. The first 48 hours of the operation were conducted better than the Second Lebanon War and Operation Cast Lead. The lessons of the Winograd and Goldstone reports were learned and internalized. Israel restored its deterrent capability without causing mass Palestinian casualties or destabilizing the region.

If the operation had ended four days ago, the message that would have been received in Gaza, Beirut, Damascus and Tehran would have been clear and sharp: Israel has excellent intelligence, decisive aerial capabilities, resolute leaders, brave citizens and surprising international support. It's not worth messing with Israel. You'd be better off letting it live its life without provoking the country or awakening it again from its slumber.

But just as in 2006 and again in 2008, Israel did not stop in time. Israel did not quit while it was ahead. And so, over the past three days, the impressive achievements of Operation Pillar of Defense have faded away while the operation's negative consequences have become more clear-cut. Israel's ability to strike at Hamas militants from the air was significantly reduced, while the harm it caused to innocent civilians significantly increased.

After recovering from its initial shock, Hamas has come to realize that it is not critically injured and that it has time on its side. Sooner or later there will be another unintentional massacre in Gaza. Sooner or later the diplomatic support Israel has received, the international-relations version of the Iron Dome missile defense system, will wane. Sooner or later Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak will be up to their ears in quicksand.

Israel must now decide which of two bad options is better: a tough cease-fire or a bad ground war. There will be no clear victory in the Gaza Strip. It is better to reach an imperfect agreement concerning the southern border than to get embroiled in a bloody ground offensive whose outcome no one can predict.

There are some demands to which Israel must not accede. For instance, the calm on the Israeli side of the Gaza border must be total; Hamas must not be allowed to rebuild its rocket supply, and the Hamas government in Gaza must rein in radical Islamic groups and pledge that the fence will not become a staging ground for provocations. But Israel must offer something in exchange, like reopening the Rafah border terminal between Gaza and Egypt, easing the naval blockade of the Gaza Strip, recognizing the de facto sovereignty and legitimacy of the Hamas government in Gaza as long as Hamas does not use its political position to attack Israel.

It will not be easy to sell the Israeli public on a cease-fire that incorporates significant achievements for Hamas. But expanding the operation, known in Hebrew as Pillar of Cloud, entails great political, regional and moral risk.

Netanyahu and Barak, along with Foreign Minister Avigdor Lieberman, must remember what happened to their predecessors after they missed the moments of grace that would have allowed them to end other wars earlier. The government must not go all the way, even if many Israelis criticize it for failing to do so. Nothing good is waiting for us at the end of such a path. It's enough. The time has come to get off the cloud and put our feet back down on the ground of reality.