Alongside the Israeli-Palestinian conflict, the gritty business of coexistence marches on. Since the Islamic militants of Hamas took over the Gaza Strip, Israel has kept the main commercial crossing point at Karni shuttered. Hamas seeks Israel’s destruction, making border crossing etiquette more precarious than elsewhere. On Wednesday, between mortar attacks by Hamas and other militants, about 20 truckloads of milk products, meat, medicines and eggs passed from Israel into Gaza, ordered by Palestinian merchants from Israeli suppliers, relying on contacts built up over years. At the fuel depot at Nahal Oz, Israeli tankers pour diesel, gasoline and cooking gas into Gaza through pipes that run beneath the border. At Karni, the Israelis have adapted a 650-foot-long conveyor belt, previously used for gravel, to send in grain. Col. Nir Press, head of the Coordination and Liaison Administration, the Israeli military agency that deals with the civilian aspects of the Gaza border, noted that in April 2006, a vehicle loaded with half a ton of explosives got through three of four checkpoints on the Palestinian side of Karni, and was stopped at the last security position by members of the American-backed Presidential Guard, loyal to Mahmoud Abbas. But the Presidential Guard is no longer there, having been routed by Hamas.