For the Israeli security establishment, it is not a question of if, but rather of when and where, Hizbullah will retaliate for the February assassination of arch-terrorist Imad Mughniyeh. As it does before every holiday, this week the Counterterrorism Bureau in the Prime Minister's Office issued a severe travel advisory against vacationing in the Sinai. Egypt claims that there are four-to-five terror cells roaming the peninsula with plans to target tourist sites. But this warning is not directly connected to the Mughniyeh alert which Israel has maintained since the Hizbullah chief operations officer was assassinated in downtown Damascus. Indirectly, however, the Mughniyeh assassination has succeeded in setting a security precedent in this country. Throughout Israel's 60 years of existence, the Shin Bet (Israel Security Agency), Mossad and Military Intelligence have joined hands - most recently during the Second Lebanon War, when the deputy head of the Mossad set up an office on the floor of the IDF Operations Directorate in the Kirya in Tel Aviv; and then surrounding the September bombing of what foreign media reports have claimed was a North Korean nuclear reactor under construction in Syria. But what is unique in Mughniyeh's case, senior officials explained this week, is that the interagency teams have been established not only to share intelligence but also to continuously analyze and assess the threat level, dividing regions and countries into different categories. The establishment of these teams indicates just how important Mughniyeh was to Hizbullah. He was not only the commander of all military forces in Lebanon, but also the mastermind behind the 2006 abduction of Eldad Regev and Ehud Goldwasser, as well as the head of all of the group's overseas operations. He personified what can be described as a nexus of terrorism encompassing the Middle East and possibly the world, serving as a link between Hizbullah and Iran, Syria, al-Qaida, Hamas and Islamic Jihad. AT A military base in the center of the country, the Shin Bet has a facility where it trains security guards who are later stationed on El Al airplanes or in embassies and consulates around the world. While it looks completely ordinary, one of the buildings there contains a long room built to replicate the interior of a passenger airliner. It is there that the security guards train, with live fire, to thwart hijacking attempts. Down the road, in another building, the agency has built a replica of the inside of an Israeli embassy abroad. This is where the security guards are trained to deal with an infiltration. Since Mughniyeh's assassination, in which Israel has denied involvement, the Shin Bet has dramatically increased its security worldwide - on civilian flights and in diplomatic missions and other institutions. Flights from India, for example, no longer take off during the day, since shoulder-fired missiles are harder to lock on a target at night. In addition, civilian flights to Europe and Southeast Asia are also being escorted by helicopters upon takeoff and landing. Ministers who travel abroad on family vacations this Pessah will be accompanied by security guards, a "perk" they have until now only received when on government trips. Hizbullah is known to have infrastructure, including sleeper cells, overseas - particularly in Africa and South America - which could be utilized in an attack against an Israeli or Jewish target. The interagency team is charged with being in constant contact with these countries' intelligence agencies to assess the threat and issue recommendations. Israel is also concerned that Iran or Syria might provide logistical support for an attack. According to intelligence information, the Iranian Revolutionary Guards maintain at least 50 "branches" around the world, although none as active as the one in Lebanon, which works closely with Hizbullah. According to the latest assessment, chances of an attack against a Jewish institution - like Hizbullah's 1994 bombing of the Jewish community center in Buenos Aires - are low on the list. More likely is an attack against an Israeli mission, the assassination of an Israeli representative abroad or an attack along the northern border. BUT, WHILE waiting for the Mughniyeh retaliatory attack, the IDF is already fighting a war in the Gaza Strip, against Hamas, which is beginning to look more and more like Hizbullah. OC Gaza Division Brig.-Gen. Moshe "Chico" Tamir knows both enemies well. He was commander of the elite Egoz unit and the Golani Brigade, and spent much of his career deep inside Lebanon. In 2005, he wrote a book called Undeclared War on the IDF's experiences and mistakes during its 18-year presence inside the southern Lebanon security zone. Following Wednesday's attack - during which three Givati soldiers were killed in an ambush across from Kibbutz Be'eri - officers in the Gaza Division could be heard comparing Gaza to Lebanon and talking about a "Hizbullah-land" that was being created just minutes south of Ashkelon. The combination of Kassam rocket fire and borderline attacks, like this one, and the infiltration into the Nahal Oz fuel depot last week, is a tactic Hamas has adopted from its northern mentor. After Operation "Hot Winter" in March, Hamas cut back its Kassam fire while increasing its activity along the border by beefing up its forces and fortifying its positions. And the border attacks are having an effect: Since the beginning of the year, eight soldiers have been killed in Gaza, in comparison to three in all of 2007. Tamir, together with OC Southern Command Maj.-Gen. Yoav Galant, has asked for permission to escalate operations in Gaza, and move from a "defensive mode" of repelling Hamas from the border to an "offensive mode" - a long-term widespread operation with the goal of hitting Hamas at its core. At the moment, however, Defense Minister Ehud Barak does not believe the time has come for such an operation. In closed talks, he compares the Kassam barrage on Sderot to the second intifada's suicide-bomb onslaught in Jerusalem and Tel Aviv. In the end, he explains, Gaza is not a strategic threat, like Iran or Syria, and therefore needs to be put into proper perspective. A self-described history buff, Barak sees that throughout the country's six decades, the government never went to war because one of its enemies was amassing weapons and an army. This was true with Egypt and Syria in the 1960s and '70s, and most recently with Hizbullah, during the six years between the unilateral withdrawal from Lebanon and the war in 2006. This, so far, has also been true regarding Hamas in Gaza, which the IDF has refrained from invading since its unilateral withdrawal almost three years ago. The IDF, however, is preparing for the possibility that additional Hamas attacks will change this pattern, and that Israel will find itself drawn into Gaza whether it likes it or not.