so, would suddenly give way to a windswept series of dunes and wadis. The map and compass helped. But I soon realized that it was almost impossible to get an accurate reading from inside the truck. Every few minutes, I waved the convoy to stop, got out, and walked fifty or sixty yards into the sand and clumps of acacia trees and calibrated our progress from there. My fallback was the stars. From them, I could at least make sure we were headed in broadly the right direction. But the need to navigate around the dunes meant we were never moving in a perfectly straight line. The miles ticking by on the truck’s odometer couldn’t tell me exactly how far we’d travelled. A couple of times, I realized we were wandering off line — not by a much, but enough to risk leaving us either a mile or two south of where we were supposed to go or, worse, on the Egyptian side of an unmarked desert frontier that, especially at night, would look pretty much the same on either side. Finally, a few hours before dawn, I brought the convoy to a halt. I climbed out, walked back to the staff sergeant and told him, with more confidence than I felt: “We’re here.” I had no way of knowing for sure. But I felt we were generally in the right place. Before we'd set off, I was briefed by the officer in charge of one of the operational APC battalions. He had been to the area before, on training exercises. Because of the emergency call-up, he was too senior to lead a supply convoy. But he told me that once we got there, we should stop and wait. He would follow our tracks the next morning and link up with us. An hour after sunrise, we saw his jeep bobbing over the sand towards us. He pulled to a stop, shook hands with the staff sergeant, and then he turned to me. “Unbelievable,” he said. “We’re where we need to be.” Our role in the grand scheme of things, and certainly mine, was hardly decisive. But the rest of the border mobilization also went to plan. That, along with some frantic diplomatic activity a