With the world busy trying to stop Iran's race to obtain nuclear weapons and American military forces stuck in the mud of Iraq, Israel is becoming increasingly concerned about its quietest neighbor these days - Syria. While Israel faces threats of terror and criminal infiltrations from Egypt and the rare attack from Jordan, the calmest front over the past 30 years has in fact been the border with Syria - where the most exciting action is the transfer of Israeli-grown apples to the other side of the border. But appearances can be deceiving, and the defense establishment now believes that with US action against Damascus a far-off theoretical possibility, Israel may need to fend for itself against President Bashar Assad's unstable regime. Security officials say Israel's latest concern is that Assad might feel so threatened by the US and the rest of the international community, and so pushed into a corner, that he might decide, stupidly, to fire missiles into the Golan Heights and beyond. While Israel's border with Syria has for the most part been quiet since the Yom Kippur War in 1973, the military's working assumption is that the country's next war could be on the northern front against Syria and possibly Lebanon - Hizbullah's stronghold. Damascus is now in a hurry to build up its army and has recently drastically increased its defense budget after close to $14 billion of its loans were erased by other countries. But while the assumption is that Syria would not attack Israel unless it was under assault by US forces, the IDF admits it has been repeatedly surprised by almost every move Assad has taken in the past two years. The assassination of former Lebanese prime minister Rafik Hariri last year and the subsequent withdrawal of Syrian forces from Lebanon turned most heads at military headquarters in Tel Aviv. The failure of Military Intelligence, the Mossad and the rest of the world to accurately predict Assad's actions is now the basis for the IDF's biggest fear - what will the Syrian leader do next? The situation in Damascus appears to be at least temporarily stable with Assad trying to jostle for time. The mid-January replacement of German judge Detlev Mehlis, who led the United Nations inquiry team into Hariri's murder, by Serge Brammertz, a Belgian prosecutor from the International Criminal Court, has given Assad some breathing space. US President George W. Bush has also reduced some of the pressure now that he faces bigger problems such as pulling American troops out of Iraq and stopping Teheran's pursuit of a nuclear bomb. At the moment, said one high-ranking IDF officer stationed in the Northern Command, the army does not see a reason to change its military deployment along the Syrian border. "We haven't changed anything," the officer said. "But we are staying alert and using our intelligence services to keep on top of anything that might happen in Syria that could have an impact on Israel." Even if the Syrian border maintains its quiet, the army does not plan to put up its feet. Security officials note that Damascus has been behind attacks against Israel carried out by its proxy - Hizbullah - on IDF military outposts in the North. According to intelligence assessments, the Hizbullah attack on an IDF position in the northern village of Ghajar last November was carried out at Damascus's and even Assad's personal behest. Henry A. Crumpton, the US State Department's chief counterterrorism official who has just visited Israel (and was interviewed by the Post on Tuesday), said recently that Syria and its leadership were serious threats to Western security. "The regime continues to support terror organizations," Crumpton told the Daily Telegraph. "And we know that the [Iraqi] Ba'athist leadership fled to Damascus, taking with them money and terrorist expertise, and we cannot rule out the fact that some of that expertise related to WMD." Israel is also well aware of Damascus's involvement in global jihad terror and on more than one occasion in recent weeks Defense Minister Shaul Mofaz has warned of the conception of a new "axis of evil" - beginning in Iran, continuing through Syria, on to Hizbullah and ending with Hamas and the Palestinian Authority. The situation on the Lebanese border carries a different tune - one that can quickly escalate from being tranquil to an all-out war, security officials say. With thousands of missiles pointed at Israel, and Israel alone, Hizbullah poses a grave threat to the North and has the IDF walking on its tiptoes not to make a single mistake that would thrust the country into an unnecessary and pointless battle with the Shi'ite militia's gunmen deployed along the border. Hizbullah leader Sheikh Hassan Nasrallah has been inspired by Hamas's victory in the Palestinian Authority parliamentary elections and according to intelligence assessments is now considering trying to pull off the same type of coup in his home country. The tit-for-tat exchanges between the IDF and Hizbullah along the border have achieved their goal and Nasrallah is now considered southern Lebanon's ultimate guardian. But he wants more, and with an eye on Israel he would like to become Lebanon's Ismail Haniyeh and take over the Lebanese government just as the Hamas leader is doing in the PA. There are also new players in Lebanon - even more daunting than Nasrallah's militiamen. In January, al Qaida forces operating in southern Lebanon fired Katyushas at Kiryat Shmona, escalating the level of attacks from mortar shells to rockets. While Nasrallah was quick to deny involvement in that attack, he might be under pressure from the new kid on the block to up the ante and use his own missiles against his enemy to the south so that he can maintain his title as southern Lebanon's supreme military leader. But while Israel is "uncomfortable" with the presence of armed Hizbullah gunmen and al-Qaida operatives so close to main roads in the north as well as the thousands of missiles pointed at Haifa, security officials say - for now - that the IDF does not plan on doing anything that could upset this delicate balance.