For all that, however, it has achieved its purpose. Since construction of the barrier commenced, deaths in terrorist attacks emanating from the West Bank have dropped precipitously. As I note in my article in the current issue of Orion Magazine,

According to figures provided by Israel’s Ministry of Foreign Affairs, between 2000 and 2003, Palestinian terrorists carried out 73 attacks, killing 293 Israelis and wounding 1,950. From 2003 to 2006, the period in which the fence was gradually erected, there were 12 attacks, killing 64 Israelis and wounding 445.

The fence should have been built along the Green Line. It should have been coordinated with the Palestinian Authority. And it should have been accompanied by an evacuation of Israeli settlements in the West Bank. If the fence is to be our security border, there is no logic to having an Israeli population live beyond it.

But when the Sharon government initiated the construction of the barrier five years ago, it presented peace-minded Israelis with a choice: an imperfect barrier that would help halt a wave of deadly terrorist attacks, or no barrier at all. Like many Israeli advocates of accommodation with the Palestinians, I decided, with great reluctance, to support the project.

In the early years of this decade, the terror offensive of the second Intifada was, for the Israeli public, the major obstacle to a process of accommodation, and a looming threat to Israeli democracy. Peace advocates could shout until they turned blue that an agreement with the Palestinians was still possible, that we Israelis held a goodly share of the responsibility for the failure at Camp David, that Israelis still fundamentally misunderstood what the Palestinians needed in a peace agreement. None of this was going to get through to the Israeli public as long as it saw suicide bombers detonating themselves on buses, in restaurants, in hotels on Seder night.

In the early 1980s, a similar upsurge in terror attacks—with a body count that we could only wish for today—led to a profound sense of insecurity in Israel. Few remember it now, but at that time public opinion surveys showed Meir Kahane’s racist Kach movement winning eleven seats in the Knesset. Fascism flourishes when people feel that their government is not protecting them.

When a person is sick, the first priority is to keep the fever from running wild; then you treat the underlying cause of the disease. Similarly, as Israel faced the new Palestinian uprising, our first priority had to be to get the death toll from terror attacks down. The barrier has helped do that.

But I realized from the start that the barrier could never be a permanent solution. It is a stopgap only.

In my post on Monday about demolishing the homes of Palestinian terrorists, I pointed out the importance of checking our anti-terror policies against the data rather than against our intuitions. Last October, Hillel Frisch of Bar-Ilan University’s Begin-Sadat Center for Strategic Studies, published a short empirical study of the separation barrier’s utility. Frisch writes that the drop in deaths from terrorism cannot be attributed entirely to the barrier; Israeli military actions were also an important factor. But the bottom line is that “[E]ven if offensive measures were relatively more effective than defensive measures, there is no doubt from the findings . . . that the fence was an important supplemental measure in achieving greater security.”

Frisch warns, however, that the terrorists will find ways to circumvent the fence. Therefore, its effectiveness will decline over time. It cannot be seen as an excuse for not pursuing, with full force, both military action (to uproot terrorists and maintain a deterrent for as long as the conflict continues) and diplomacy (to reach an accommodation with the Palestinians that will address the root causes of terror attacks).