When asked in 1787, as the Constitutional Convention in Philadelphia came to an end, whether it had created a monarchy or a republic, Benjamin Franklin replied, "A republic, if you can keep it."



His pessimism comes to mind whenever a republic makes a terrible mistake, from the French policy of appeasement toward Germany in the 1930s to the American policy of incrementalism in Vietnam to the South Korean "sunshine policy" now under way.



Franklin's worry felt newly relevant on Thursday last week, as the state of Israel effected a most extraordinary swap with Hezbollah, one of the world's leading terrorist groups.



In exchange for one rogue Israeli civilian, captured while possibly engaging in dubious transactions, plus the remains of three soldiers, Israel released 429 living terrorists and criminals, including 400 Palestinians, 23 Lebanese, five other Arabs, and one German, as well as 59 corpses.



It comes as little surprise to learn, in the description of the New York Times, that this exchange prompted "a day of national celebration" in Lebanon and a "somber" mood in Israel. Nor is it astonishing to hear the Israeli prime minister, Ariel Sharon, describe the present as "not a time of happiness."



Mr. Sharon went on to explain his motives in carrying out the exchange by referring to the relatives of the dead Israeli soldiers: "Three dear families, whose souls knew no rest for the past 40 months, will now be able to unite with their sorrow over a modest grave, and composure as a promise was kept, and a right and moral decision was made despite its heavy price."



In other words, a major decision of state was taken for the sake of bringing small solace to three families. But what are the strategic consequences for Israel of this act of seeming morality?



* Some, or many, of those 429 will again engage in terrorism against Israel, perhaps sparking a whole new campaign of violence. That is what happened once before: In 1985, Reuters explains, the Israeli government "swapped more than 1,100 Palestinians for three missing soldiers. Seven hundred Arabs were allowed to stay in the occupied territories and many later became leaders of the Palestinian uprising that erupted in 1987."



* The lopsided deal signals Israel's enemies that they can extract huge benefits by taking even just one civilian Israeli hostage. Itamar Marcus of Palestinian Media Watch has collected many Palestinian statements drawing this conclusion.



The military branch of Fatah "emphasized the necessity to follow in the footsteps of the act of Hezbollah, so that all prisoners and detainees will be released." A Hamas leader saw in this deal confirmation that terrorism "is capable of achievements to liberate the land and people." A newspaper hails Hezbollah for opening "a new door of hope for the families of the prisoners, after it was closed during the political solutions between the [Palestinian Authority] and Israel, which did not lead to any practical results."



* Israel's reputation and standing undergo severe damage from this signal of demoralization and vulnerability. Listen to Ali Khamenei, Iran's supreme leader, on the exchange, seeing in it another proof "that the evil Zionist regime is defeatable by the strong wills and concrete faiths of the mujahedeen of Islam."



The Sharon government also failed its allies in the global war on terror.



Hostage-taking looks like a more effective tactic than it did a week earlier. If it can win a signal victory for Islamists in Lebanon against Israel, their ideological counterparts are more likely to use it in Iraq against the American government, in Moscow against the Russian government, and in Kashmir against the Indian government. Each terrorist success, however local, has the potential to reverberate internationally.



The moral opprobrium of dealing with terrorists is eroded. If releasing hundreds of terrorists is acceptable for Israel, why not other countries, too?



These many negative consequences raise questions about the morality of this Israeli government action.



In its early decades, Israel's strategic prowess was legendary, transforming a weak country into a regional powerhouse. The past decade has seen the opposite process, whereby that powerhouse reduces itself to a tempting target. That this change is entirely self-induced and achieved through the democratic process makes Benjamin Franklin's prophetic concern all too real.



When will the descent stop? By then, how much damage will have been done?



[This article originally appeared in the New York Sun of February 3, 2004.]