[4] His equally firm opposition to the fast rise of the fascist Iron Guard (the Legionnaires, a group he helped outlaw in January 1931),[7][6] contributed to the fall of the 1933 Vaida-Voevod government of which Călinescu was a member.
[8] In opposition to the Gheorghe Tătărescu PNL cabinet, Călinescu warned against the latter's tolerant stance toward the Legionnaires,[9] especially after the murder of Ion G. Duca in December 1933 and the desecration of his memorial plate in 1936 ("The Iron Guard is not a movement of the [public] opinion, but rather an association of assassins and foul profaners of tombs").
[1][11] Eventually, he defied his party by becoming Minister of the Interior after December of that year, in the short-lived Octavian Goga cabinet formed by the National Christians,[12][13][14] being immediately expelled from the PNȚ.
[17][13] He soon became involved in a virulent dispute with historian Nicolae Iorga, when the latter issued harsh criticism regarding Carol's January 1939 initiative to dress large sections of the society, including Romanian Academy members, in various uniforms (a measure backed by Călinescu);[18] Iorga remarked with irony: "I'm prepared to wear the FRN uniform, but allow me to wear a speared helmet on my head, on which to place [that is, to impale] the Minister of the Interior".
[20] In May, after witnessing the result of German pressure on Austria (see Anschluss),[21] Călinescu decapitated the Guard by ordering arrests of its leaders, beginning with that of Codreanu,[22][23] as well as many of its members and sympathisers (including Nae Ionescu and Mircea Eliade).
[28][23] On 7 March 1939, after brief stints as Minister of Health and Minister of Education,[1][13] he replaced Cristea as Premier upon his death, being considered the "man of steel" able to prevent the Iron Guard's political rise and to keep Romania out of the pro-German war camp[29][2] (the nickname "The Man of Steel" probably originated, under the form l'homme d'acier, in essays written by the French journalists Jérôme and Jean Tharaud on Romanian topics).
In September of that year, after the invasion of Poland, certain members of Iron Guard alleged that Călinescu and the King Carol planned with the British Intelligence services to blow up the Prahova oil fields, preventing Germany from taking control and using them.
[38][35] A more severe repression of the Iron Guard followed under the provisional leadership of Gheorghe Argeșanu and was inaugurated by the immediate execution of the assassins and the public display of their bodies at the murder site for days on end.
One year later, under the National Legionary State (the Iron Guard's government), Marinescu and Argeșanu, alongside other politicians, were executed at Jilava Prison (September 1940); it was also at that time that the Călinescu family crypt in Curtea de Argeș was dynamited,[39][40][44] and a bronze bust of him which awaited unveiling was chained and dragged through the streets of Pitești.
[39] Călinescu's wife Adela was required to hand all of her husband's personal documents and, in a letter to Conducător Ion Antonescu, claimed to have been repeatedly harassed by agents of Siguranța Statului.