Security officials have said that the suicide bomber who murdered three Israelis in Eilat on Monday was the "tip of the iceberg." "The threat has not fully materialized even with this suicide attack," a high-ranking IDF officer from the Southern Command told this newspaper. "I am concerned that this is just the beginning and the attacks will continue." According to the officer, security forces have caught over 100 Palestinian terrorists who took the same route as the Eilat suicide bomber: crossing from Gaza into Egypt, then from Egypt into Israel. Among the terrorists caught were suicide bombers and weapons experts on their way to establish terror infrastructure in the West Bank or to plot kidnappings of Israeli soldiers. None of this should be terribly surprising. Brig.-Gen. Imad Faris, who heads the division in charge of patrolling the Israeli-Egyptian border, said that it runs 200 kilometers without a fence or "any other mental or physical barrier." The border between Gaza and Israel, by contrast, has been fortified for the last few years by an elaborate system of fences that has largely succeeded at preventing the infiltration of terrorists. A fence is not a panacea, of course. Gilad Shalit was kidnapped by terrorists who tunneled under the Gaza fence. Kassam rockets have been flying over the Gaza fence. Fences are no substitute for demanding that those on the other side do their part to stop the terrorists and smugglers who originate in their territory. Still, it is hard to imagine a single IDF officer who today would argue that the Gaza fence system is not worth every shekel it cost to build and costs to maintain - even though the idea of constructing it was controversial within the IDF before it was set up. Similarly, it took over a year of suicide bombings before Israel seriously debated the merits of building a security fence in Judea and Samaria, and it remains incomplete to this day, even in the Jerusalem area. Yet here too, security officials have sung the praises of those portions of the fence that have been built, and have credited it with preventing untold numbers of terrorist attacks. It has even been noted that, though some Palestinians complain bitterly over how the fence has made their lives more difficult, life in many Palestinian towns improved greatly after the fence was built since the IDF was able to greatly reduce its operations in those areas. Given all this, it is natural that the construction of a security fence on the border with Egypt has been under consideration for some time as well. Just after the disengagement from the Gaza Strip in the summer of 2005, security officials began warning of a potential "terror triangle" connecting the Gaza Strip, Egypt and Israel. To address this, the IDF drew up a plan called "Hourglass," under which a 220-km electronic fence would be built along the entire border from Gaza to Eilat. Also in 2005, prime minister Ariel Sharon called for building the first 50 km of this fence near Eilat. In the end, however, only NIS 100 million - out of the NIS 1.5 billion needed - was appropriated for the entire project. As expensive as a Sinai border fence would be to build, we suspect that, as was the case with other such projects, all involved will consider the money well spent once it is built. This particular fence, moreover, would serve multiple purposes. The border with Egypt is not only an entry way for terrorists; it is a source of rampant smuggling of goods, weapons and people. The sordid and illegal business of trafficking in women might be largely shut down by the proper closure of this border. Fighting criminal activity in the Negev, which has reached unacceptable proportions, would be greatly facilitated by making life much more difficult for the smugglers. Finally, the Egyptian border is the primary conduit for weapons and terrorists moving from Gaza to the West Bank - where the security fence is also incomplete. As expensive as it is, then, the "Hourglass" plan should be funded and implemented. If, as the name implies, we all know it is a matter of time, many lives might be saved and much good achieved if that time is sooner rather than later.