Four years ago, when the United States and Great Britain brought Saddam Hussein's rule in Iraq to an end, there was a collective sigh of relief within the Israeli defense establishment. The "Eastern Front" had ceased to exist. The nightmare scenario of the Republican Guards' armored brigades sweeping across the lightly defended Hashemite Kingdom to attack Israel on its long and unfortified Jordan Valley border could be taken off the list of threats. Nor would Hussein's Scud missiles be once more pointed at Tel Aviv. The Ba'ath regime was finished and the American presence would prove a counterbalance to any hostile military coalitions. But already at the time, that was hopelessly outmoded strategic thinking. The last time the IDF fought a regular army was when it decimated the Syrian contingent in Lebanon in the 1982 war, and even then, it wasn't a full-scale war between the two armies. The border on the Golan Heights remained quiet. For more than three decades, ever since the Yom Kippur War, the Arab states haven't tried to use their conventional forces against Israel. The IDF's supremacy is too overwhelming and the region's rulers need their armies to keep their subjects in line. In that sense, neither Iraq nor any of Israel's neighbors is a real threat. But nevertheless, the outcome in Iraq will almost certainly have significant implications for Israel. Next week is the fourth anniversary of the launch of Operation Iraqi Freedom, an event that will be marked by anti-war demonstrations and special programs on the international news channels. But on the ground, there will probably be little sign that it's a special date. There will be the same deadly routine of car bombs, roadside explosive devices and ambushes in the cities and towns of Iraq, and the same interminable political wrangling in Washington over the future of the US military involvement. Two facts, though, seem unavoidable. Any prospective president planning to win the November 2008 US election will have to promise a clear time frame for extricating American troops. And whenever that evacuation is over, there will still be sizable groups of terrorists of various stripes and colors holding out who will celebrate the US departure as their victory. At that moment, the Eastern Front will once again become a threat for Israel. When Prime Minister Ehud Olmert, addressing the AIPAC conference in Washington this week, warned against a "premature" departure and stressed the importance of "American success in Iraq, and a responsible exit," he should have been reserving the warnings for his own generals and intelligence chiefs back home. US Vice President Cheney might have echoed Olmert by speaking out against a retreat "that would leave our worst enemies dramatically emboldened," but in less than two years, Cheney will have ended his long career in Washington. A new president will begin working on fulfilling his election pledges and we'll still be stuck in the Middle East with the same bad guys. Whatever success the Americans will have in the time remaining to them in damaging the terror groups and stabilizing the new Iraqi government, the moment they leave, Iraq will once again be a source of threat to Israel - not from tanks and long-range missiles, but from the kind of highly-motivated, well-trained guerrilla soldiers the IDF faced in Lebanon last summer. Thousands of Islamist fighters, both Sunni and Shi'ite, will be anxious to take on "Little Satan." Flushed with what they will obviously see as their success at having evicted Big Satan from the land of Islam, they will believe that the same thing can be done to the Zionist entity. Their arrival will boost the capabilities of Hizbullah, Hamas and the other Palestinian terror groups and further encourage them to seek violent confrontations with Israel. Any response now to the new Hamas-Fatah Palestinian government should take into account this expected development a couple of years down the road. The long overdue comprehensive training program the IDF is currently undertaking is designed to prepare the troops for every kind of scenario. The high-profile exercise carried out by the Paratroopers Brigade on the Golan Heights recently was meant as a show of strength clearly visible to Syrian eyes. The intensive training going on at specially constructed installations, designed to emulate the asymmetrical warfare against small phantom guerrilla units of the kind the IDF experienced in the North against Hizbullah, will most likely be much more relevant over the next few years, also to the East.