Smuggling into the Gaza Strip from Egypt beneath the Philadelphi Corridor has returned to the busy levels that prevailed before Operation Cast Lead last winter, The Jerusalem Post has learned. Estimates of how many tunnels are now functioning range from several hundred to 1,000, although the most authoritative figures indicate that between 350 and 500 are currently operating. The IDF claimed to have destroyed about 300 tunnels during Cast Lead. Israel has long asserted that the Egyptians could put an end to the entire smuggling industry within 24 hours if they wanted to, using military obstructions along the length of the Philadelphi Corridor. But it does not want to - in part because the trade is an integral part of the economy in Sinai, and in part because it is not only arms that are being smuggled into Gaza, the Post has learned. Vital supplies are being brought in as well, and Egypt is unwilling to sever that link so long as Israel maintains its blockade on the Strip. The concern in Egypt is that a crackdown on Hamas's smuggling industry would produce anti-government demonstrations in Cairo that could undermine President Hosni Mubarak's regime. Israel had noted a marked reduction in the smuggling into Gaza after Cast Lead, but over the past few months, and especially the last few weeks, it has reverted to its former scale. Fully laden trucks pull up alongside the entrances to the tunnels, often just meters from where Egyptian soldiers are deployed. But the Egyptians do nothing to thwart the smuggling, the Post has learned. The US, which has provided technical assistance to Egypt in thwarting the smugglers, has been engaged in a dialogue with Cairo over the issue, without much success. It has also been working toward providing aid to local Egyptians so that they need not rely on smuggling for their livelihoods. An indication of the continued traffic came in October, when Hamas test-fired an Iranian-made rocket with a range of 60 km. According to defense officials, Hamas likely has long-range rockets capable of reaching Tel Aviv. Many in the Israeli security establishment anticipate that sooner or later, Israel will have to mount another military offensive against Hamas in Gaza. On Friday, IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi said, "If we will need to, we will operate again in the Gaza Strip to stop the rocket fire." Israel's stated aim in Cast Lead was to put a halt to rocket fire across the border, deal a major blow to Hamas's terror infrastructure and create conditions under which it would not be able to rearm. Although the Hamas regime has been depicted as being on the point of collapse toward the end of Cast Lead, the then-government of prime minister Ehud Olmert chose not to continue the operation, in good part because of the concern that Israel would be left in military control of the immensely hostile Strip and would find itself unable to extricate itself for years. Meanwhile, Israel has been hearing suggestions from traditionally supportive American politicians that it consider lifting the blockade - to reduce Gazans' dependence on the Hamas-controlled tunneling and smuggling industries, and as a gesture to bolster Palestinian Authority President Mahmoud Abbas. There is still widespread concern in both Israeli and American government circles over Abbas's declared intention not to seek reelection, even though the scheduled January 24 PA elections have now been postponed. Echoing calls from the US administration, many senior coalition figures and members of the security establishment are urging the government to quickly consider a range of measures that might bolster Abbas and weaken Hamas - including alleviating the Gaza blockade and transferring greater responsibility in the West Bank to PA security forces, the Post has learned. The performance of the PA forces is said to be far better than at any time in the past 15 years. It is also recognized that a deal to free kidnapped IDF soldier St.-Sgt. Gilad Schalit, which could involve the release of hundreds of Palestinian security prisoners, would further bolster Hamas and weaken Abbas. Hence the need for steps to strengthen Abbas and his Prime Minister Salaam Fayad.