John Maynard Keynes, the great economist, once said in a debate: "When the facts change I change my mind, what do you do, sir?"
Well, like it or not, the facts are changing. From the Sinai in Egypt, a country that has a signed peace treaty with Israel, terrorists are entering Israel and killing Israelis. And the Egyptian government, the military junta that has replaced Hosni Mubarak's dictatorship, is unwilling or incapable of assuring peace on the Israeli-Egyptian border. There may be more acts of terror emanating from Sinai to follow.
Diamonds may be forever, but treaties with dictators are not. They are of limited duration, they last as long as the dictatorship lasts, and in this day and age that is well short of forever.
It is now 34 years since Israel agreed to turn the Sinai peninsula over to Egypt as part of the peace treaty signed by Menachem Begin and Anwar Sadat. Although many do not like to be reminded of it, Sadat was a dictator. The peace treaty survived his assassination four years later, when he was replaced by Mubarak. Whether it will survive the downfall of Mubarak is not clear at the moment.
When it was signed, Arab dictatorships were considered to be a permanent feature of the Middle East. It seemed obvious that Israel had to make peace with Arab dictators, and that the formula for making peace with them was "territories for peace" - giving up territorial strategic assets for peace with a dictator.
That peace is security was considered a tautology. Dictators were famous for their ability to enforce their will upon the people. When they signed a peace treaty you could depend on them.
You would expect Israel, a democracy, to welcome the downfall of dictatorships in neighboring countries, and see the Arab Spring bring freedom to the Arab World. But in recent months we have learned to our dismay that the downfall of Arab dictators may bring in its wake chaos and anarchy and the threat of the ascendancy of the Muslim Brotherhood.
On a number of occasions successive Israeli governments came close to reaching a peace agreement with the Syrian dictator Hafez al-Assad, prepared to trade the Golan Heights for peace with him. Today we can consider ourselves fortunate that such a treaty was not signed. What is happening in the Sinai could have been happening now in the Golan Heights.
We have little choice but to prepare for a continuation of an unpleasant situation and hope that whoever rules Egypt in the years to come will adhere to the peace treaty with Israel, and will realize that putting an end to the chaos in the Sinai is of common interest to both countries.
But most important, we must realize that the facts on the ground around us are changing, and that there may yet be more changes in the wind. It is time for a reappraisal of pre-conceived ideas.
This is not a time to throw caution to the wind. This is not a time to withdraw to the 1949 armistice lines. It is not a time for "daring political initiatives." It is a time for watching and waiting to see how things are going to turn out. It is a time to think how we are going to assure the security of Israel's citizens in the southern part of the country from daily rocket attacks, and make sure that those living in the north and the center of the country do not share their fate.
Iron Dome is a great technological achievement but it alone cannot do the job.
It is a time to put away the placards calling for "Peace Now" and "An End to the Occupation." It may be the time for those demanding "social justice" for the "middle class" to fold their tents.