"This is a war," a high-ranking member of the IDF General Staff said Sunday. Not just a war against the Kassam, he explained, but a full-fledged war the State of Israel was waging against Palestinian terrorism. But while the IDF has talked tough for months, issuing declarations every so often that it would "crack down" on Kassam launch cells, only over the weekend did the army really begin to put its fire where its mouth was. The results were evident - 15 Palestinians dead and dozens others wounded. The army, like any business enterprise, operates based on the principles of cost-benefit analysis. In the current case, the equation is quite clear: yes, the Kassam instills fear in the Negev, but it causes minimal damage and so far not a single Israeli has been killed by the primitive rocket in a direct hit since disengagement some nine months ago. On the other hand, senior officers say matter-of-factly, the IDF would definitely pay a heavy price with soldiers' lives were it to conduct a ground operation into Gaza. With that formula in mind, IDF chief of General Staff Lt.-Gen. Dan Halutz is not rushing to enter the Gaza Strip and will continue doing everything possible from the air, sea and ground (outside Gaza) before he hands the Southern Command invasion orders. But other IDF officers say that "Southern Arrow" - the name of the IDF operation against the Kassams - was taking a natural course that would inevitably lead to a massive ground operation inside the Gaza Strip. "We have no problem entering Gaza tomorrow," one high-ranking officer said. "It is all a matter of when we feel that we have fully utilized this current stage in the operation and we need to escalate our action to continue creating deterrence for the other side." So while the army says it is satisfied overall with the IAF air strikes in Gaza over the weekend, officers predicted the current intensification would last for a few weeks, after which another escalation or "step up" would be required - eventually culminating with troops on the ground in Jabalya and Khan Yunis. That is exactly how the IDF's anti-Kassam campaign began. At first, the army set up artillery cannons that fired hundreds of shells a day at empty fields in the northern Gaza Strip. The next stage brought back targeted killings of Palestinians involved in the manufacture, deployment and launching of the rockets. The third stage, which began over the weekend, was the bombing of terrorist training camps in Gaza and the integration of Navy warships in the daily barrages. The army also didn't take seriously Islamic Jihad's reported offer of a cease-fire on Sunday in exchange for a halt to the IDF operation. Islamic Jihad, officials explained, was not a movement that Israel was open to negotiating with; those who were really responsible for the Kassam fire, they said, were Palestinian Authority Chairman Mahmoud Abbas and his new Hamas-led government. But the Kassams might turn out to be the least of the IDF's problems on the Gaza front. While only one Katyusha rocket has so far been fired at Israel (on Election Day), Military Intelligence believes the Palestinians have at least 100 more. In addition, the army suspects that Palestinians may have also gotten their hands on anti-aircraft missiles and other new weaponry. Iranian and Syrian terror and bomb experts, officers say, have also entered Gaza through the Rafah crossing with Egypt and are in the midst of setting up new terror infrastructures with the goal of duplicating them in the West Bank. So while the army for now might be comfortable watching the Kassams take flight from outside Gaza, Halutz might soon need to order troops inside to curb the terror flow and once and for all stop the rocket fire.