He was assigned to the 38th Infantry Regiment in March 1915, and from July to September 1916, during which time Romania entered the war, he attended the reserve officers' school in Târgoviște.

[4] The appointment to this post, left vacant upon the departure of Gusti, prompted a fierce battle within the faculty that drew the attention of the contemporary press.

The latter faction was joined by Garabet Ibrăileanu when Petrovici promised to support Mihai Ralea's appointment after the latter's return from France; and by the new dean, Traian Bratu, a bitter adversary of Găvănescu and his ally Orest Tafrali [ro].

[3][7] Attracted by its promise of deepening bourgeois democracy, Andrei joined the new National Peasants' Party (PNȚ) in 1928, becoming president of its Vaslui County chapter.

He spoke memorably of the role of parliament in the nation's political life, and worked to pass modern legislation, particularly in the fields of education and administration.

On the one hand, his character and civic impulses recoiled at the idea of dictatorship; nevertheless, he joined forces with what he saw as the only viable means of preserving domestic order, maintaining the country's traditional pro-French foreign policy, and crushing the Iron Guard.

In early October, while Iron Guard members were searching his home and due to be arrested, he committed suicide,[3][10] swallowing potassium cyanide.

[12] After World War II, the authorities of the new communist regime arrested his son Petru for having taken part in student anti-communist demonstrations; he was imprisoned from 1949 to 1952.

Initially banned, the work of Petre Andrei was censored, with all passages referring to communist concepts, doctrine and practice excised, even from an authoritative edition published in the 1970s.

Later in the decade and into the 1980s, Ovidiu Bădina and Romanian Communist Party ideologue Ștefan Voicu [ro] engaged in a polemic on the value of Andrei's work.