A REMARKABLE pilgrimage site stands outside the town of Siauliai: a mound covered in a dense forest of crosses placed by devout Lithuanians who, for two centuries, have come here to pray for God’s help and liberation from occupiers. The Soviet authorities tried more than once to bulldoze the site, only to see it reappear. After independence the now-sainted Pope John Paul II left a large crucifix in 1993. Scattered on the hallowed ground are crosses planted by passing contingents of NATO airmen; these days they, too, provide protection in the heavens.Siauliai’s air base tells its own story of fragile statehood. Built by the pre-war Lithuanian republic, it was occupied by Stalin’s forces, then by Hitler’s Luftwaffe and then yet again by the Soviets. It was finally reclaimed by the Lithuanians, who now host NATO’s air-policing mission. Amid decaying Soviet concrete hangars, modern Western jets bristling with missiles are ready to take off at a few minutes’ notice. Pilots will not discuss encounters with Russian planes though their wall has pictures of intercepted Sukhoi-27 fighters. In one incident last year, Russian bombers carried out a dummy night-time attack on…