This politician justified a turn to austerity by claiming that it would “open a parenthesis.” This politician gained leadership at the Épinay Congress after losing an election as the leader of the FGDS alliance. A rival party leader refused to use the Observatory Affair to discredit this politician, who lost his seat in 1958 when the SFIO did not remove its candidate. This politician named a doctrine against extraditing terrorists (10[1])convicted over acts from the Years of Lead. Gaston (-5[1])Defferre was an important ally of this president, whose Defense Minister Charles Hernu resigned after the sinking of the Greenpeace (10[1])ship Rainbow Warrior. (10[1])As president, this politician entered the first “cohabitation period” after appointing Jacques Chirac as his prime minister. For 10 points, name this first President of France from the Socialist Party. ■END■ (10[2])