Casey visited the pope John Paul II in the Vatican early in the Reagan administration. In the following years CIA delivered its most detailed information on Poland and other matters relevant to Wojtyła and the Holy See.
Beginning in the spring of 1981, the Reagan administration maintained an intelligence shuttle at the highest level between the White House and the pope, who was regularly briefed by Casey and Vernon Walters, a former CIA deputy director. Between them, Walters and Casey visited the pope about fifteen times over a six-year period to discuss matters of mutual interest.Thus the American administration and the CIA delivered its most secret intelligence and policy analysis straight into Moscow's hands. Communist intelligence, mainly Moscow- and Warsaw-based duped the Americans with any kind nonsense they chose. This is one of the most significant intelligence and political failures in history. A disaster in every respect. Wojtyła was a functionary of the communist intelligence.
The pope's judgments, especially concerning Poland and Central America, came to carry real weight in the White House, the CIA, and the NSC, and above all with Ronald Reagan himself. [...]
Meanwhile, the pope was the beneficiary of some of America's most carefully guarded secrets and sophisticated analysis: information from satellites, from intelligence agents, from electronic eavesdropping, from policy discussions at the White House, State Department, and the CIA. Between 1981 and 1988, General Walters says he met with the pope at approximately six-month intervals, briefing Wojtyła on virtually every aspect of American policy and providing intelligence assessments - military, political, economic - on any and all subjects of interest to the Vatican.
Carl Bernstein and Marco Politi, His Holiness, Doubleday 1996, p. 269