Israel's approach to Hamas over the past year is a case of climbing a ladder. The first rung is made up of the economic sanctions Israel has imposed on the Gaza Strip, starting with the closure of the Karni crossing over the past year, and running to the proposal currently being deliberated to stop the supply of fuel and electricity. The second rung is the almost daily IDF operations in Gaza, conducted - as on Thursday - up to three kilometers inside the Strip and aimed at maintaining a strong defensive posture and preventing Hamas from establishing positions on the border, planting bombs or digging terror tunnels. The third rung is the targeted-killing onslaught that Israel unleashed this week on the Islamic Jihad terror group, behind the daily Kassam rocket fire into the western Negev. All of these rungs lead up to the final step in Israel's attempt to pressure Hamas into stopping the terror and reining in Islamic Jihad. If none of them works, Israel will be left with only one rung - a full invasion of the Gaza Strip with the declared goal of destroying Hamas. Senior defense officials were not surprised by the Foreign Ministry's assessment on Thursday that 2008 will be the year that Israel goes to war in Gaza. The thinking within Jerusalem that a large-scale operation in Gaza is the only real way for Prime Minister Ehud Olmert's peace partner, Palestinian Authority President Mahmoud Abbas, to return to power in the Strip has been floating around the halls of the Kirya Military Headquarters for several months now, ever since Hamas's violent takeover of Gaza in June. There is no question that the IDF can, if it unleashes it full power, significantly weaken Hamas, and perhaps destroy it. Israel would first bomb Hamas positions from the air and simultaneously begin assassinating Hamas's military, and possibly even political, leadership. The IDF has learned its lessons from the Second Lebanon War and would fairly early on send large forces into Gaza for two purposes - to stop the Kassam rocket fire that will escalate in the first few days of the operations and to hunt down terrorists by going door-to-door on Gaza's densely-populated streets. It would also most likely take up positions in the Philadelphi Corridor next to Sinai to stop the weapons smuggling into Gaza, as well as in the northern Gaza Strip, the launch pad for many of the Kassam rocket squads. But before all this begins, the question that needs to be asked is what price Israel is willing to pay for such an operation. Official estimates talk about more than 100 dead soldiers, possibly even more than the 119 killed during the Second Lebanon War. Hamas is no longer a small terror group; it has a full-sized military in Gaza, armed to its teeth and highly-motivated to fight. The bigger problem is the exit plan. "It is easy to go in, but more difficult to get out," a senior defense official said recently. With the IDF, as well as the Shin Bet (Israel Security Agency), not all that sure that Abbas is capable of grabbing the reins and retaking Gaza, there may not even be a reason to go in there to begin with.