Not surprisingly, in his final case - on the legitimacy of targeted assassinations - Aharon Barak arrived at just the sort of Solomonic compromise for which he is famous. According to the unanimous panel's ruling, Israel may preemptively target and kill terrorists, but it may not kill former terrorists as punishment for past deeds. Before conducting an assassination, though, the military must establish by conclusive evidence that the target is involved in a terrorist plot or plots, and it must show that it could not arrest the target without substantial risk to the lives of Israel soldiers. These are the precisely the factors that I outlined in my book Preemption, that any moral government, committed to the rule of law, must satisfy before engaging in any sort of preventive or preemptive action. Further, if any innocent civilians are killed in the operation - as they sometimes, tragically are - Israel is bound to compensate their families. And finally, the court reaffirmed proportionality as the guiding principle behind any such assassination, as it is the centerpiece of the rules of engagement in all civilized nations. The Supreme Court, and Barak in particular, have come in for undeserved criticism from the right for many of the justice's most famous opinions. In 1999, the court issued its famous ruling outlawing any and all coercive interrogation techniques, and in 2004 the court ruled that Israel has a right to a security fence, but that its route must take into account the rights of Palestinians. But the court showed in this case what its supporters knew all along - that the driving force behind those opinions was a respect for democracy, human rights and accountability, rather than any dogmatic political ideology. No democracy, despite what it might publicly profess, can forgo a policy of killing those who it is reasonably certain are trying, and have the capacity, to kill its own citizens. The stakes are simply too high to rely on after-the-event criminal sanctions. And indeed, as former president Bill Clinton has acknowledged, even though America officially opposes targeted assassinations against terrorists, the CIA and Defense Department were hard at work during his administration trying to hunt down and kill Osama bin Laden and his ilk. On the other hand, once a person is no longer implicated in a terrorist plot, the Israeli Supreme Court held that he or she is no longer subject to assassination. Punishing people for what they have done is a matter left exclusively to the criminal justice system. This finding accords with the Geneva Conventions, which, as the court noted, instructs that "[c]ivilians shall enjoy the protection afforded by this section, unless and for such time as they take a direct part in hostilities." Once that time has ended, so too has the threat to Israeli civilians. No matter how justly a person deserves retribution, only a court may mete out sanctions. And in the end, it is precisely the power of courts and the rule of law in Israel that is so eloquently demonstrated by this opinion. Where else but in Israel are issues of national security debated in open court sessions, and then explained to the public in written opinions? Barak's final ruling is a testament to his own career, his court, and to the best in human rights laws worldwide. Alan Dershowitz is a professor of law at Harvard. His most recent book is Preemption: A Knife that Cuts Both Ways (Norton, 2006).