[Reprinted with permission. First published Jan 21, 2011]

My neighbor on the page where my weekly column appears in Yisrael Hayom, Yossi Beilin, commented last week that Israel was returning to the idea of "defensible borders," which in his words was "anachronistic" and had been "disproven" since it was first introduced through UN Security Council Resolution 242 in 1967. Today, he argued it was a completely "ridiculous" concept in light of the technological changes that have been introduced by the IDF--and among our enemies.  Beilin asks how this idea could be relevant when we are  in "a world of missiles."
 
Yet, there are important professionals outside of Israel who have looked at Israel's situation recently and have rejected this thesis that "defensible borders" no longer matter. For example, Lt. Gen. Earl B. Hailston, who was the commander of US Marine forces in Iraq and Afghanistan in 2003 and 2004, commented several years ago: "It is unthinkable that Israel would return to the '67 borders in the West Bank, which would deny the Israeli people the defensible borders that are vital for them. Even in the era of advanced military technology there is a decisive importance to strategic depth and terrain conditions for national security."
 
During a conference in Washington in 2005, Gen. John Foss, the former commander of the U.S. Army's  82nd Airborne Division also stated: "As a soldier I would tell you that the pre-'67 borders are not defensible in the long run for Israel. They absolutely cannot live with those borders with those distances". Military men, like Foss, recognize that the military echelon will come under pressure from the political echelon to make compromises when Israel draws its final border, but that does not alter their professional military view that defensible borders contribute to national security in the 21 st century. 
 
Still it is fair to ask what is the logic behind defensible borders if missiles can fly right over them? In answering this question, the American generals who fought two wars in Iraq understood a fundamental principle of military strategy: wars are not decided by missiles or any other form of firepower, but rather by the movement of conventional armies. For example, in the first Gulf War in 1991, Iraq was struck by thousands of American cruise missiles and bombs, but Saddam Hussein only surrendered to the US-led coalition when American tank formations occupied a third of Iraq and the road was open to Baghdad. The same principle applied in 2003, as well.
 
In the Israeli context, defensible borders were never conceived to hermetically seal off all threats to Israel, but only to deny any enemy ground force the ability to exploit the numerical inferiority of  the IDF's standing army and win a decisive victory against Israel through invasion and the seizing of its territory. It should be remembered that in 1973, 177 Israeli tanks on the Golan Heights had to hold off  a total Syrian force of 1400 tanks. The unique topographical conditions of the Golan Heights enabled the IDF to withstand the quantitatively superior Syrian assault and to ultimately carry the war into Syria thereby forcing Damascus to accept a cease-fire.
 
In fact, in the age of missiles, defensible borders have grown in importance. In the past, Israel needed 48 hours to complete its reserve mobilization in order to reinforce its small standing army deployed along its borders. But once Israel becomes vulnerable to an attack by ballistic missiles, or even short-range rockets, which delay its reserve mobilization, then Israel's standing army may have to fight for longer periods of time without reinforcement from the reserves. Moreover, the Israeli Air Force may not be in a position, under these circumstances, to help block a ground attack. Israeli aircraft will will have a new mission to find and destroy missile launchers across several countries in the Middle East, in order to suppress missile attacks on Israeli cities, and will not be far less able to deal with close air support at the earliest stages of a future conflict.
 
It will be argued that these scenarios were relevant before 1991, when Israel feared that a third of the Iraqi Army would join the Eastern Front and attack Israel, as it did in 1948, 1967, and in 1967. Today the situation is very different. But strategic planning must not be based on snapshot of reality that could easily change again. Iran has been developing close relationships with many of the Shiite politicians who dominate the new Iraq: indeed in the Wikileaks cables, Saudi Arabia's King Abdullah described Iraqi Prime Minister Nouri al-Malki as "an Iranian agent" who "opened the door for Iranian influence in Iraq." The cables also disclosed that Iran has been investing $100 to $ 200 million a year in Iraqi politicians. It would only be prudent to consider that Iraq could become an Iranian satellite, after the US withdraws the last of its troops.
 
Moreover, beyond the issue of conventional wars, it is now clear how vital defensible borders are for the war on terrorism. Israel is one of the only countries  that has faced Radical Islam on the battlefield, without having to deal with thousands of foreign volunteers, like in Afghanistan, Yemen, Iraq, or Somalia. Israel has been able to keep out of the West Bank weapons that "would alter the balance, " because it controls the Jordan Valley (after the loss of the Philadelphi route, much of this weaponry entered Gaza in huge quantities) . For a while in 2005, al-Qaeda\Iraq established a forward position in the Jordanian town of Irbid. Today, Hezbollah is already in Iraq. Should Israel concede the Jordan Valley, and its right to defensible borders in the east, then the battlefield against Hamas on the outskirts of Tel Aviv would completely change.
 
Finally, those dismissing defensible borders as an antiquated concept, generally believe that Israel can rely on its own massive firepower to crush its enemies in any future war. There used to be voices that said borders don't matter because "after we withdraw, if they dare fire one Katyusha, we will erase their village." Those statements ignore the reality of Israel's recent wars. Certainly, one of the main lessons that Israel has had to learn is there are limits to the use of firepower that the world considers legitimate, even in a completely just war. Thus Israel needs to find a balance between addressing its territorial differences with its neighbors and limiting its vulnerability which its adversaries have shown that they will always seek to exploit.

This article originally appeared in Israel Hayom on January 21, 2011