On my first visit to Israel, in the early 70s, I paid a visit to the Black Widows, a group of women whose spouses had fallen in one of the state's wars. I vividly recall what one widow whose husband was killed in the 1967 Six-Day War tearfully told me: "For the entire nation, this war was a joyous event - a miracle, really, that comes along just once in a lifetime. But for those of us left bereaved, it is a calamity from which we shall never recover." For the families of our kidnapped soldiers, the release of their sons will no doubt be an event of unparalleled celebration. But if it comes at the price of releasing upon our populace hundreds of bloodthirsty killers and terrorists, it will be a disaster of tragic proportions. We Jews hold life to be of inestimable value. The mitzva of pidyon shvuyim (redemption of captives) has always been a high priority. Yet as fiercely as we cherish life, there are boundaries to maintain and exceptions to make. There are times when the imperative of saving one life clashes with the obligation to save many. In such complex situations, a difficult triage must be conducted, as two intrinsic goods are weighed against each other. Freeing mass murderers from prison - even in exchange for one of our precious soldiers - invariably yields disastrous results. It mocks the concept of law and order: Why should anyone refrain from "trivial" crimes - such as traffic violations, theft or tax evasion - if the punishment for killing another human being is dismissed? In civilized societies, wanton killers remain locked up. Would the US free Sirhan B. Sirhan, James Earl Ray or Charles Manson? Freeing killers returns Israel to the law of the jungle, to the days of vigilantism where, in the absence of a credible justice system, next of kin exact revenge on those who murdered their loved ones. Releasing Palestinian terrorists also has a chilling, demoralizing effect on our security forces. Brave soldiers fought mightily, even died, to bring these killers to justice; setting them free mocks the troops' noble efforts. It is also tantamount to dancing on the graves of terror victims. What would we say to the Roth family, whose daughter Malki was killed in the Sbarro bombing, or to David Hatuel, whose wife Tali - 8 months pregnant with their first son - along with their daughters Hila, Hadar, Roni and Merav, were gunned down by Palestinians in 2004? But most of all, freeing large numbers of killers always yields new waves of death and destruction. According to the Almagor Terror Victims Association, in the past five years, 177 Israelis were killed by Palestinians freed from prison and "sworn" to non-violence. Our government should be sympathetic to the captured soldiers' families, but at the end of the day, its first allegiance must be to the safety of its citizens. Let's be honest - the prisoners swap under debate is not about Gilad, Ehud and Eldad. Even if their families were to courageously object to unleashing a new wave of terror on the public in return for their sons - just as Jonathan Pollard has nobly refused to be traded for Marwan Barghouti - our present leadership would seek the swap nonetheless. According to the government's misguided "wishful" thinking, the Palestinians must be offered endless, one-sided concessions, which invariably only strengthen their resolve to destroy us. Our sages tell us that "he who saves one life saves an entire universe." That may be true, but it does not justify destroying countless other universes in the process. The writer is director of the Jewish Outreach Center of Ra'anana, and father of Sgt. Ari Weiss, killed in a Hamas raid in Nablus in 2002.