The IDF put on an impressive show Tuesday during its annual Joint Forces Exercise, held at the Armored Corps's Shizafon training base just north of Eilat. Hundreds of soldiers participated in the drill, which is the Ground Forces' yearly opportunity to demonstrate its most advanced platforms and fighting capabilities. The two-hour show started with a pair of F-16s dropping 500-pound bombs on an enemy position. Tanks and artillery fired shells, and Cobra attack helicopters provided air support and cover for infantry forces. Engineering Corps vehicles laid out makeshift bridges to enable armored personnel carriers and tanks to advance toward their target - a Syrian village. The exercise, which costs several million shekels in fuel and ammunition, is conducted in honor of the graduating class of Officers School cadets designated for commands in the Ground Forces. It is also a way for the IDF to display its fighting capabilities to the world. A year-and-a-half after the Second Lebanon War, the IDF is still working hard on rehabilitating its various branches. The exercise helps raise morale among troops and show the world that the military is ready for conventional war with Syria, or low-intensity conflicts against Hizbullah and the Palestinians. But sitting in the crowd were not only cadets, soldiers and officers. Between the uniforms was an inconspicuous middle-aged couple who had flown down to Shizafon on a Yasur helicopter - the IAF's name for the Sikorsky CH-53 - together with OC Ground Forces Maj.-Gen. Avi Mizrahi. When Defense Minister Ehud Barak arrived at Shizafon under his usual tight-belt of security, the first thing he did was go over to the couple and give the woman a kiss and the man a hug. Barak knows them well. When he was prime minister in 2000, their son, Sgt. Adi Avitan, was abducted by Hizbullah in an attack near Mt. Dov, together with two of his fellow soldiers - Benny Avraham and Omar Sawaid. Their bodies were returned in January 2004. The IDF traditionally invites bereaved parents to attend drills and exercises, and Mizrahi had personally requested that Tzipora and Ya'acov Avitan join him on the trip to the South. Their presence at the drill was a stark reminder that while the IDF is building up its forces - and is in the midst of unprecedented training regimens and weapons procurement - there are still three soldiers who have yet to return home: Gilad Schalit from the Gaza Strip, and Ehud Goldwasser and Eldad Regev from Lebanon. IN THE midst of all of this, Chief of General Staff Lt.-Gen. Gabi Ashkenazi will celebrate his first anniversary in the top military post this week. Even with the year behind him, Ashkenazi still has his work cut out for him, recently confessing in a closed forum that, despite all the operational challenges he deals with daily, he still feels that his primary job is rehabilitating the IDF. The need for rehabilitation was laid out in detail in the Winograd Report released last week, and concerns not only operational failures, but a breakdown in military culture as well. "Had we only fought like this during the war in Lebanon, it would have ended differently," was how some officers described the feeling on the sidelines of the massive exercise at Shizafon this week. As a tough Golani Brigade veteran, Ashkenazi believes in victory through direct contact with the enemy while utilizing strong, mobile ground forces. His version of weapons development and procurement includes better armor, advanced command-and-control systems and improved firepower for troops on the ground. While the Iranian threat looms, Ashkenazi's most immediate challenge is the situation in the Gaza Strip and curbing terrorism from the West Bank which, as was demonstrated this week in Dimona, is far from disappearing. Though initial claims of responsibility for the attack were made by terror groups in Gaza, the terrorist duo actually infiltrated from Hebron, south of which there is a 26-kilometer gap in the security fence. And though that gap is worrisome, the IDF is more troubled with the situation in Gaza, and, as was reported exclusively in The Jerusalem Post on Thursday, the defense establishment is drawing up plans to reconquer the Philadelphi Corridor between Gaza and Egypt, and its dozens of tunnels used to smuggle weapons and terrorists in and out of the Strip. The purpose of such an operation is to seal off the border that was brought down by Hamas two weeks ago, to uncover the tunnels, draw out terrorists and discover the new weaponry that has been smuggled into Gaza. Ashkenazi is not excited about the possibility of having to invade Gaza - either in a large-scale operation or a more limited one, focusing on the Philadelphi Corridor. Casualty estimates are high, and a senior officer admitted this week that there is still no definitive exit strategy. The best bet would be for Palestinian Authority President Mahmoud Abbas and his Fatah party to pick up where the IDF leaves off, but it is not at all clear that he is capable of doing so. THE ATTACK in Dimona on Monday was significant, because it demonstrated the urgency of building fences in the southern Hebron Hills. But it was also the first suicide attack carried out by Hamas since August 2005. Hamas has also dramatically increased its Kassam rocket attacks, from 65 in November, to 113 in December and 241 in January. All of this explains why the growing assessment within the defense establishment is that a large-scale operation in Gaza is not a question of "if" but of "when." In response to the Dimona attack, Israel bombed a Hamas installation in southern Gaza, killing nine. Hamas then sent a barrage of rockets into Sderot, wounding three. On Thursday, the IDF raided Gaza, leaving seven dead, and Hamas fired nine rockets into Sderot, sending several people into shock, and causing extensive damage. With the collapse of the border wall between Gaza and Egypt, there are fears in the defense establishment that the Palestinians have now obtained longer-range and more sophisticated and accurate rockets. Iran is believed to be behind Hamas's recent rocket upgrades, and has stepped up its involvement in the Gaza front. As far as the IDF is concerned, there is no easy solution to the Kassam attacks. The IDF could invade Gaza in a large-scale operation that would be costly for both sides; according to recent estimates, Israel could lose more soldiers in Gaza than the 119 killed during the Second Lebanon War. The other option is to heavily bomb Gaza in response to each rocket attack, and risk heavy collateral damage and strong international condemnation. Trying to avoid these two extremes, Ashkenazi has been pushing a middle ground that includes clamping down economically on Gaza and at the same time keeping up a steady flow of pinpoint operations like the one that killed seven gunmen near Jabalya on Thursday.