Be careful venturing into Central Park at night during the next few weeks. The overall crime rate is still low, but don’t be surprised if a war is going on, and a Trojan Horse appears suddenly and blocks the bridle path. The hallowed outdoor stage of the Delacorte Theater will be home to ancient Greeks uniformed in camouflage fatigues, sporting crew cuts and running about to the booming sounds of heavy artillery and overhead choppers.