What if you looked out of your window and noticed a group of men on a nearby roof training what appeared to be shoulder-held anti-aircraft launchers at jetliners approaching the airport? Or what if you had good reason to suspect that the new upstairs neighbors had transformed their apartment into a makeshift explosives laboratory? Plainly, you would call the police - out of a sense of both obligation and self-preservation. Likewise, the same moral, legal and commonsense rules would prevail if you were to stumble upon a group of heavily armed men fleeing down a flight of basement steps in your hospital, or sneaking crates marked "Danger Explosives" into your local mosque. So here is a revolutionary idea: Apply these same principles in southern Lebanon and the Gaza Strip. INTERNATIONAL humanitarian law obligates parties to an armed conflict, including non-state actors, to take every feasible precaution to protect civilian populations against attack. Clearly, the overriding obligation is not to place military targets among civilians. The intentional use of civilians to render certain areas immune from attack is illegal under international law. For instance, taking over a family's house and transforming it into an arms cache is a form of human shielding, and illegal. It is true that international law permits retaliating against homes, places of worship, hospitals, schools and cultural monuments which are illegally being used by terrorists. But there ought to be a better way. Why not encourage - perhaps somehow even obligate - the denizens of southern Lebanon and Gaza to conduct themselves as if they lived in Liverpool or Chicago or Barcelona? When you see a war crime in the making, report it. The need for some fresh thinking on this score is made urgent not just by the patently inequitable Goldstone Report, but by the deaths late Monday of Said Nasser Abdel Issa and his son (along with three others, according to Arab media reports) when the arms cache in their home blew up. The incident took place in the village of Tayr Filsay, on the southern bank of the Litani River, about 10 km. from the Israeli border. Hizbullah identified Issa as one of its "brothers," so, in this instance, the homeowner was party to the placement of the explosives. Israeli authorities know there are hundreds of weapons stores in other homes, mosques and commercial properties throughout southern Lebanon. The explosion came on the heels of the explosion on July 14 of the Hizbullah arms depot in Khirbat Salim, which ignited a fireball seen miles away. Both incidents illustrate that Hizbullah, which controls southern Lebanon and is a powerbroker in Lebanese politics, continues to flagrantly violate UN Security Council Resolution 1701, the basis of the cease-fire being observed by Israel. OF COURSE, Shi'ites in southern Lebanon and Palestinians in Gaza sympathize with the respective goals of Hizbullah and Hamas. But even those who may oppose using UN facilities, school, hospitals, ambulances and private homes to stage their "resistance" against Israel can't simply pick up the phone and call the cops - without reaching the bad guys themselves. That is why the civilized world needs to set up a mechanism, something akin to an Interpol hotline, which could handle tips in anonymity and, perhaps, even offer a witness protection scheme. It makes no difference if the affected civilians sympathize with the goals of those who have commandeered their dwellings, or if they have been cowed into collaborating. Standing by with folded arms while your neighbors smuggle weapons into a tunnel below the village square is wrong. Islamist extremists employ attacks against enemy civilians while shielding themselves among their own people - a sort of 21st-century poison gas. This leads to retaliatory attacks - as in Afghanistan, Iraq, and here in our region - costing the lives of innocent noncombatants. One way the civilized world can preserve its values as it confronts "militants" who have no compunction about flying airliners into skyscrapers or sending suicide bombers to blow up buses is to reduce the chance that civilians will be injured in retaliatory strikes. And the best way to do that is by encouraging the local population to start taking some responsibility for its own safety.