THE Palestinian protesters massed at the fence expected tear gas and rubber bullets; what they got instead was a putrid yellow wind, Israel's newest weapon against West Bank demonstrators. The noxious mist, which Israeli police refer to as "skunk," was used for the first time earlier this month, when a truck-mounted cannon sprayed it over the heads of protesters, sending them racing down the hillside, retching and tearing off their shirts to try to escape the stench. Dozens of Palestinians from the village of Bilin, along with international and Israeli activists, had marched to a nearby segment of Israel's controversial...