MEDIATION:THE BIGGEST hurdle to achieving a ceasefire in the Gaza Strip, according to diplomats and Israeli military officials, is how to stop Hamas from digging tunnels into Egypt in order to bring tonnes of rockets and other weaponry into Gaza.
Mediators are trying to come up with an anti-tunnel plan to satisfy Israel, which has said it will not agree to a truce unless it includes concrete measures to prevent Hamas from rearming. Some of the ideas under consideration include construction of a giant underground barrier along the nine-mile border between southern Gaza and Egypt, as well as international military patrols with the authority to search for and destroy any freshly built tunnels, Israeli officials said.
Israeli military officials estimated that they had blown up about half of the estimated 300 smugglers' tunnels along the Gaza-Egyptian border since Israel began air strikes on December 27th.
Maj Avital Leibovich, an Israeli military spokeswoman, claims that Hamas used the tunnels to acquire 100 tonnes of explosives in the past year, among other supplies. "They basically smuggle everything from people to rockets," she says. Israel has imposed an economic blockade on Gaza since Hamas took exclusive control of the territory in June 2007, and Gazans have used the tunnels as their only means of trade with the outside world.
Israeli leaders acknowledge that the Gaza military campaign can only serve as a short-term fix and that Hamas will probably dig a new network of tunnels as soon as the Israeli military withdraws. As a result, they say any ceasefire deal would need to include a provision for blockading the Egyptian-Gaza border, both above and below ground.
Israel has effectively sealed off Gaza's eastern and northern borders, and closely patrols Gaza's western side along the Mediterranean. But it has accused Egypt of turning a blind eye to the tunnels in the south, even though the 1978 peace accord between Israel and Egypt limits the security forces that each country can deploy along their shared border.
Israel's military had warned that smuggling would become a problem before it withdrew its soldiers and settlers from Gaza in 2005 and considered a variety of schemes to thwart potential tunnel diggers. The most audacious idea was an 80-foot-deep moat filled with sea water.
But the military vetoed the moat proposal after Israel's attorney general said he would oppose it because of fears it would contaminate Gaza's scarce underground water supplies. A plan to dig a giant dry trench was also shelved because it would have required the destruction of hundreds of Palestinian homes along the border corridor.
Those and other plans to construct a subterranean barrier have been getting another look since Israel reinvaded.
Roni Bart, a retired Israeli army colonel and a research associate at the Institute for National Security Studies at Tel Aviv University, says a Gaza barrier would cost far less and probably generate much less political controversy than the 456-mile long security barrier - which includes fences, roads and walls - that Israel is building around much of the West Bank.
A senior Israeli official who briefed reporters on the military campaign did not rule out the possibility that Israel would attempt to construct an underground physical barrier along the Gaza-Egypt border. Mark Regev, a spokesman for Israeli prime minister Ehud Olmert, said Israel was open to any plans that would block Hamas from digging more tunnels.
"There are different ideas out there and the Israeli government is willing to hear the input of the international community," he said.
Israeli officials and analysts say any ceasefire deal would hinge on co-operation from Egypt, as would construction of an underground barrier.
Israeli leaders have rejected ceasefire proposals that would involve sending international observers to Gaza, saying that such teams would be ineffective unless they had the authority to destroy tunnels or engage Hamas fighters. "It's clear that we don't need monitors to tell us that, 'Today, 10 tonnes of armaments passed through the tunnels'," Mr Regev said. "We need a mechanism that will work, but what form that might take is fluid."
Egyptian officials haven't said whether they would allow foreign troops or monitors on their side of the border.
Hamas has said that it will only agree to a ceasefire if Israel agrees to reopen border crossings from Gaza and end the blockade.
Officials with the Palestinian Authority, which holds power in the West Bank and is led by political rivals of Hamas, say they favour allowing international observers into Gaza as part of a truce. But they have been reluctant to endorse a plan that would give outsiders police powers and the authority to destroy tunnels.