VIENNA — Norway has become the ninth European country to sign up for French nuclear protection in light of heightened alertness vis-à-vis Russia and broadly faltering trust in U.S. reliability. The announcement came following a visit by the Norwegian prime minister, Jonas Gahr Stoere, to Paris last week. Also present in Paris were delegates from other European countries that had signed up for what France bills as “forward deterrence,” a still nebulous but historically significant redefinition