There are times when it's a good idea to assassinate a Hamas leader, even in a foreign country, and times when it's a bad idea. The killing of Mahmoud al-Mabhouh in Dubai last month (which everyone presumes to have been the Mossad's work) was a bad idea. By contrast, the Mossad's attempt in September 1997 to kill Khaled Mashaal in Amman was a good idea that went bad in the execution, so to speak, as I wrote in a column titled "Hit 'em back" two weeks afterward.

What's the difference? Why was Prime Minister Binyamin Netanyahu right to order the hit on Mashaal but wrong to order (as we all presume he did) the one on Mabhouh?

The difference is that in 1997, Hamas was focused on one activity - killing as many Israelis as possible. They did so partly for the sake of killing Israelis, of course, but more for the strategic purpose of destroying the Oslo peace process and overthrowing Yasser Arafat and the Palestinian Authority. About 100 of Hamas's killings, according to Israeli officials, had been ordered by Mashaal himself.

"So our choice is harsh but simple: We can either kill them back, or let them kill us with impunity. We can play eye for an eye, or let Hamas play uncontested," I wrote in October 1997.

That was then. Today, things are completely different. Today, Hamas is not trying to kill as many Israelis as possible, it's trying to maintain a cease-fire on the Gazan-Israeli border while attempting to rebuild. In the West Bank, it's on the run from the PA police and the IDF.

And when it comes to killing, Hamas has been getting much, much the worst of it from Israel for many years.

SO WHY did the Mossad presumably, reportedly, allegedly assassinate Mabhouh? The only killings Israeli officials have tied him to are the two he himself took "credit" for: the 1989 kidnappings and shootings of soldiers Ilan Sa'adon and Avi Sasportas.

I don't believe the Mossad would mount an operation like the one in Dubai to avenge the killings of two soldiers 21 years ago.

The only plausible motive was to stop Mabhouh from doing the other thing Israeli officials blame him for: smuggling weapons from Iran into Gaza.

But I'm sorry, smuggling weapons is not the same as killing people. In 1997 we could say, as we did with the would-be Mashaal assassination, that we are trying to make peace with the Palestinians, we're not trying to kill them, so any Palestinian who goes on killing Israelis leaves us no choice: killing him is the only way we can protect ourselves.

Yet what are we saying with the Mabhouh assassination? One thing - that the Palestinians have no right to weapons of war. This goes for Gaza especially, because of Hamas and the groups there even worse than Hamas, but no Palestinian entity anywhere has the right to arm itself. Not even if it becomes a recognized state, not even if it's run by the likes of Mahmoud Abbas and Salam Fayyad, not even if it signs a peace treaty with Israel.

This is our policy: We have the right to unlimited military power - what we call self-defense - while the Palestinians have the right to none.

This is wrong. Secondly, the Palestinians will never accept it. Israel presumably, allegedly, etc. took an incredible risk in Dubai, is paying a heavy diplomatic price for it, and, above all, has provoked Hamas and its allies to try to even the score. Why? To defend the principle that we alone are the armed sovereign power between the river and the sea.

BY COMPARISON, the principle that the Mossad was defending in Amman 13 years ago was this: When Israel and its enemies are trying to make peace, but some of its enemies are still making war, Israel has no choice but to hit 'em back.

That was right, that was fair, that was something we could reasonably expect Palestinians to absorb, and, above all, it was a principle worth taking major risks to defend.

In 1997, in the middle of the Oslo accord, with Hamas determined to kill its way to power, the assassination of its masterminds, such as Mashaal, was Israel's last option for security.

Today, with Hamas holding its fire in Gaza, with a peace government in Ramallah, there are all sorts of things we can do to protect ourselves before calling for the Mossad.

We can lift the blockade of Gaza and thereby lift the desperation of the Gazan people. We can join the rest of the world in accepting the Palestinians' right to a sovereign state based on the pre-Six Day War borders, not the subservience-with-a-flag that Netanyahu's offering them. We can talk turkey with Abbas and Fayyad. We can grow the hell up.

As the Bible says, there's a time to kill and a time to heal. On that basis, we should have put our hit squads on inactive duty a good few years ago. Enough with the James Bond routine; it's old. Everyone around here is winking and chuckling; Meanwhile, time is passing us by.