Operation "Hot Winter" was the last large IDF incursion into the Gaza Strip. It took place early last month, lasted less than a week and exacted more than 120 Palestinian casualties. Days after the IDF pulled out of Gaza, reports began to surface of a cease-fire in the works between Israel and Hamas. Weeks went by during which Hamas completely stopped its Kassam rocket fire and groups like Islamic Jihad drastically reduced theirs. The understanding in the IDF's Southern Command at the time, and specifically in the Gaza Division, led by Brig.-Gen. Moshe "Chico" Tamir, was that a level of deterrence had been achieved by the damage and the casualties Hot Winter had inflicted on Hamas. On Wednesday, that deterrence completely wore off, as Hamas showed that in the weeks since the operation it may have cut back its rocket fire, but at the same time, it dramatically fortified its positions and beefed up its forces along the border with Israel. Hamas, the IDF believes, has recently come to understand that its Kassam rocket attacks were not having the desired effect: They were not killing Israelis in Sderot or in other Gaza-belt communities, and more importantly, they were swaying world opinion in Israel's favor and legitimizing IDF operations in Gaza. Hamas's change in tactics and decision to invest in cross-border attacks is not new for the IDF. Israel faced a similar situation during its 18-year presence in southern Lebanon, when it fought daily against Hizbullah guerrillas to maintain the security zone. Still, the Gaza border attacks are having an effect - since the beginning of the year, eight soldiers have been killed in and near Gaza, compared to three killed in all of 2007. Southern Command officers who studied the terrain and deployment of forces involved in Wednesday's attack by Hamas said it was nothing more than classic military tactics and demonstrated the extent to which Hamas had changed from a small terror group into a full-fledged army. Two terrorists were spotted by reconnaissance units moving toward the border in northern Gaza. An IDF force that crossed the border to engage the terror duo found itself under fire from a secondary unit that had positioned itself in an elevated position to provide cover for the two terrorists who were laying the bomb. Last week's terror infiltration at the Nahal Oz fuel depot was also a classic military operation that came straight out of Hizbullah's playbook. Then, terrorists laid down a cover of mortar fire over the crossing, providing the necessary distraction for the four terrorists who cut a hole in the fence, entered directly into the depot and opened fire, killing two Israeli truck drivers. Both of these operations show how Israel has lost its deterrence against Hamas. While Operation Hot Winter exacted a heavy price from Hamas and got the group to stop its rocket attacks, the two recent attacks - this Wednesday and last - demonstrate Hamas's adoption of Hizbullah tactics and the emphasis it is putting on the fight over the fence. By keeping the fight close to the fence, Hamas also believes it will be able to stave off a larger IDF operation deeper inside Gaza and keep the Israeli incursions limited to three kilometers inside the coastal Strip. The IDF has had some impressive successes in its fight over the border, and according to a Southern Command officer, since the beginning of the year, troops have "destroyed" more than 30 terror cells spotted, like the one on Wednesday, operating near the border.