There is a heightened sense in the security establishment that a broad-scale ground incursion inside the Gaza Strip is necessary this summer to deal a severe blow to Hamas's infrastructure, sources in Jerusalem said Wednesday, following the death of three soldiers in a Gaza ambush. According to the sources, the incursion - similar but more difficult than Operation Defensive Shield in the West Bank in 2002 - would not take place until about a month or a month-and-a-half after US President George W. Bush's planned visit here in mid-May. By then, the last of the world's leaders to have come here to celebrate the country's 60th anniversary would have left. The timing would also place the operation in the middle of summer, considered an optimal time for this type of operation. The sources said there was recognition that such an operation would be extremely costly, both in terms of soldiers and Palestinians killed. Nevertheless, the operation is being considered out of a widespread sense that the current situation in the Gaza Strip cannot continue festering indefinitely. The sources said the idea would be to "clean Gaza out" and deliver a devastating blow to the considerable Hamas military infrastructure that has been built up there over the last few years - largely with Iranian and Syrian support - through the relentless smuggling of arms. According to the sources, Israel would have no intention of remaining inside Gaza, but rather would hand it over for administration to either Egypt or a third party. While admitting that neither Egypt nor a third party such as NATO, the EU or the UN would be too excited about taking over responsibility for the Strip, the sources said Hamas's recent breach of the border with Egypt was a significant "wake-up call" for the Mubarak regime, which has become increasingly concerned that Hamas now poses a considerable threat to Egypt. The sources pointed out that the head of the Defense Ministry's Diplomatic-Security Bureau, Amos Gilad, has shuttled back and forth to Cairo a number of times in recent weeks for talks with top Egyptian security officials. Last week, Channel 2 reported that Egypt was, for the first time, considering the deployment of troops inside the Gaza Strip. Back in December, EU Middle East envoy Marc Otte told The Jerusalem Post that the mechanism for an international security presence in the Gaza Strip "could be devised quickly" if an agreement on the matter were reached between Israel and the Palestinians. A senior official in the Prime Minister's Office, when asked Wednesday about the likelihood of a broad-scale IDF action in the Gaza Strip, neither confirmed nor denied that such plans were in the works, saying only that "we have made clear that we hold Hamas responsible for the situation in the Gaza Strip, and will hold them accountable." One top officer in the Southern Command, meanwhile, said that the IDF was prepared for a large-scale operation in the Gaza Strip if ordered to do so by the political echelon. "We have already prepared for a long time many different scenarios, including a large-scale invasion of Gaza," the officer said. "It is up to the level above us to give the order." Yaakov Katz contributed to this report.