(Catholic nuns wave as busloads of clergy arrive to welcome Pope Benedict XVI at the Basilica of the National Shrine of the Immaculate Conception in Washington, April 16, 2008. REUTERS/Jonathan Ernst )

When Pope John Paul II arrived in the United States in 1979, the president of the nation’s most powerful organization of nuns met him with a challenge. In a bold welcoming address, Sister Theresa Kane called on the pope to include women “in all ministries of our church,” including the priesthood. The pope sat silent, his expression stony.

That moment did not change Vatican policy. But it unveiled growing tensions between the Vatican and American nuns. The conflict would continue to mount for the next three decades, until this week the Vatican finally moved to reassert control over the aging but still ferociously independent conference of Catholic sisters.

In a stinging “doctrinal assessment,” the Vatican accused the Leadership Conference of Women Religious – an umbrella group representing most American nuns – of numerous grave breaches of doctrine and decorum.

The report, four years in the making, found that the nuns promoted political views at odds with those expressed by U.S. Roman Catholic bishops, “who are the church’s authentic teachers of faith and morals.” The Vatican chastised the nuns for airing discussions about the ordination of women, the church patriarchy and ministry to gay people.