Why did Eugenio Pacelli negotiate a concordat with Nazi Germany in 1933?

Eugenio Pacelli, serving as the Vatican's secretary of state under Pope Pius XI, negotiated the 1933 concordat with the Nazi regime based on the belief that the interests of the Roman Catholic Church could be more effectively secured through formal diplomatic agreements than by relying on nation-based political parties acting on the Church's behalf.1

This strategy was consistent with the Vatican's broader approach at the time, which sought to preserve the Church's privileges, rights, and freedom of action within a country through international law, even when dealing with regimes hostile to Christian principles. Pacelli, who had previously served as a nuncio in Germany and was familiar with the political landscape, viewed such pacts as a primary tool for protecting ecclesiastical affairs. Despite these intentions, the agreement failed to shield the Catholic community in Germany from subsequent interference and persecution by Nazi authorities.213