Initially a critic of Nazi Germany, he would go on to serve as a minister in the collaborationist regime. Although Barthélemy was position on the moderate right he was attracted to because of the initial approval of the new regime shown by his mentor Charles Maurras. In this role he signed the 1941 law that brought in the section spéciales, a supposedly counter-terrorist measure that in fact gave these new bodies the power to pass down life imprisonment and death sentences without the right of appeal.
After the war Barthélemy would claim that he had only signed this law under pressure from Interior Minister Pierre Pucheu.
Indeed, Barthélemy sought to portray Pucheu as a hard-line Nazi and a man with a taste for intrigue, conspiracy and violence and as such passed much of the blame for his own wartime record onto Pucheu. However Barthélemy also endorsed anti-Semitic laws, later seeking to justify his actions by claiming that the Jews in pre-war France held a disproportionate amount of influence.
Barthélemy"s legal background saw him work closely with Xavier Vallat in framing laws against the Jews, notably the second Statute on Jews in 1941. In 1943 the Ministry of Justice passed to Maurice Gabolde although Barthélemy retained a high profile as he led the proceedings against Léon Blum in the infamous Riom Trial.
Barthélemy was arrested in October 1944 and imprisoned before being transferred to hospital where he died the following year.
As one of the leading French Catholic intellectuals of the 1930s, Barthélemy was initially noted as a strong critic of Nazism, in particular the anti-Semitism of the movement.
Académie des Sciences Morales et Politiques]
Active as a Democratic Republican Alliance member of parliament from before the war, he succeeded Raphaël Alibert as Minister of Justice in February 1941.