ROME – As Joseph Cardinal Ratzinger, the newly elected Pope Benedict XVI had since 1981 been prefect of the Congregation for the Doctrine of the Faith, the Vatican’s enforcer of doctrinal purity.

It is a job that he appears to have taken to with enthusiasm, bringing him into confrontation with the forces of modernism and secularism in the church – liberation theologians, homosexuals, feminists, and religious pluralists.

His German origins and relish for a doctrinal fight earned him inevitably the nickname “Panzerkardinal,” a term which will no doubt drop into disuse now that he has acquired the majesty of the Throne of St. Peter.

With his silver hair and spectacles, he looks nothing like a tank commander; rather a cultured and bookish man. He is, however, outspoken, having described rock music as “a vehicle of anti-religion” and dismissed Protestant churches as “deficient.”

His harsh image was somewhat softened when he presided over the funeral Mass for his predecessor, Pope John Paul II, when he was seen to weep for the man who had been his spiritual mentor. The cardinal said that “we can be sure our beloved pope is standing today at the window of the father’s house, that he sees us and blesses us.”

As prefect of the Vatican’s doctrinal watchdog, he was the successor to the Inquisition – a fact that none of those he clashed with over doctrinal issues will let him forget.

His first battle was with Liberation Theology – the blend of Marxism and Catholic doctrine nurtured by intellectuals in Latin America, which held that the church should engage in a Robin Hood-like struggle to better the lives of the poor.

When Pope John Paul II visited Latin America in 1979, he found Liberation Theology flourishing. In 1984 the then Cardinal Ratzinger tore apart the doctrine with “An Instruction on Certain Aspects of the Theology of Liberation.”

The Latin American bishops were forced to remove elements of revolutionary socialism. The Brazilian, Leonardo Boff, was “silenced” and later left the priesthood.

This set the tone for holding the line on other aspects where, in the view of conservatives, the forces of modernism and secularism were challenging the eternal verities of the church.

In Germany, he stopped Catholic bishops taking communion with Lutherans. He was held responsible for banning Catholic priests offering counseling to pregnant girls. In view of the reigning liberal ethos in Germany, his stance has made him a controversial figure in his homeland, utterly different from the adulation accorded his predecessor by the Poles.

He was born in 1927 in Markt am Inn, between Munich and Salzburg, into an anti-Nazi family. His wartime youth colored his later years. In his memoirs, he recalled deserting from the German army in May 1945.

In 1941, a young Ratzinger, 14, and his brother, Georg, were enrolled in the Hitler Youth when it became mandatory for all boys. Soon after, he records in his book, “The Salt of the Earth,” he was let out because of his intention to study for the priesthood.

In 1943, like many teenage boys, he was drafted as a helper for an anti-aircraft brigade, which defended a BMW plant outside Munich. Later, he dug anti-tank trenches. He recalled how he deserted in May 1945.

“In three days of marching, we hiked down the empty highway, in a column that gradually became endless,” the future pope recalled. “The American soldiers photographed us, the young ones, most of all, in order to take home souvenirs of the defeated army and its desolate personnel.”

At the time, he knew that the SS units would shoot a deserter on the spot – or hang him from a lamppost as a warning to others. He recorded his terror when he was stopped by other soldiers.

“Thank God they were ones who had had enough of war and did not want to become murderers,” he wrote. “They had to find a reason to let me go. I had my arm in a sling because of an injury.”

“Comrade, you are wounded,” they told him. “Go on.”

Soon, he was home with his father, Josef, a policeman of Bavarian farming stock, and his mother, Maria.

After he returned home, the Americans finally arrived – and set up their headquarters in his parents’ 18th-century farmhouse on the outskirts of the town.

They identified him as a German soldier, made him put on his uniform, put up his hands, and marched him off to the town square, where other prisoners were kept. He wound up living under the open air for several weeks, surrounded by barbed wire.

He finally was released on June 19 and hitched a ride on a milk truck back to Traunstein, where his family had moved a year after his birth.

He was ordained into the priesthood in 1951, and became the archbishop of Munich in March 1977.

Four months later, Pope Paul VI made him a cardinal, meaning he was one of only three cardinal electors to select the new pope who was not appointed by John Paul II.