Gaza ground war?

Tony Karon and Aaron Klein:

For more than a week now, Israel's armored columns have been poised at the edge of Gaza, carefully drawn battle plans in hand, ready to launch the ground component of the military campaign to deter Hamas from firing rockets into Israel. Even as the Israeli air force pounded Gaza for a seventh day and Palestinian rocket fire continued, the soldiers living in and around their tanks and armored personnel carriers in the winter cold, on a constant state of high alert against mortar fire and possible guerrilla raids, were wondering out loud about what's holding back their political leaders from giving the green light. And the flirtation with various cease-fire proposals earlier in the week by the man in charge of Operation Cast Lead, Defense Minister Ehud Barak, has prompted a revival within the ranks of the nickname "Zig-Zag" — originally applied to Barak in reference to his skittish diplomacy as Prime Minister in 2000, ahead of the failed Camp David summit.

Although the air war has so far claimed more than 400 Palestinian victims, and continues to inflict damage on Hamas — as well as, inevitably, on the civilians around it — Israelis believe the attacks have not yet delivered the deterrent blow they desired. Nor did that change as a result of Sunday's strike that killed top Hamas political-military figure Nizar Rayan. Although the assault on one of the movement's most senior figures has been interpreted by Hamas as an intentional body blow — and may yet prompt a furious retaliation — Israeli officials did not characterize it as a "targeted killing." Indeed, Israeli military-intelligence sources tell TIME that Rayan was killed when he remained in his home after Israel had phoned and ordered those inside to evacuate — before striking to destroy command facilities in the house. Israel says it has used this "knock on the roof" practice of phoning warnings about strikes on the homes of Hamas leaders throughout the current campaign. Israeli officials say the campaign thus far has not significantly targeted or damaged Hamas' leadership and chain of command. (See pictures of Israel's campaign in Gaza.)

The answer to the question of what's restraining Barak and Prime Minister Ehud Olmert from launching a full-scale ground attack may be found in the goals of the Israeli operation and the time available. Israel has made clear from the outset that its objective is to attain a cease-fire on its own terms that will last at least a year or two. While they hope to weaken Hamas, Israel's leaders are aware that they're unlikely to destroy the organization, and among their primary concerns is to avoid getting dragged into a quagmire. Destroying Hamas would take a massive invasion of all of Gaza, but it would also require an open-ended reoccupation of the territory, a trap Olmert and Barak will avoid at all costs.

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The troops with those tanks are the safest people in Israel within range of Hamas rockets, since they have not been fired on at all. Of course they have counter battery radar and can immediately fire artillery at any attacking force. They will probably use an artillery barrage to clear the area where they intend to invade for those looking for a signal to the invasion.

What they are waiting for beyond any political considerations is a shaping of the battle space. The more the IAF can degrade the Hamas fighting capability the less costly the invasion will be.

If Barak or Olmert lose their nerve before using this force they will be making a gift to Benjamin Netanyahu the leader of the Likud party.