John Paul's unease over the state's use of force was perhaps first evident in his earlier treatment of the death penalty: that while it may be acceptable in principle, the state now has alternatives that make it all but impossible to justify in practice.
The linkage is not only mine. In recent interviews, Archbishop Renato Martino, head of the Pontifical Council for Peace and Justice, explicitly says that classic just-war teaching may now be headed the way of the death penalty. When the National Catholic Register asked the archbishop if he meant by this that "there is no such thing as a just war anymore," his answer was unequivocal: "Absolutely."
The pope has not gone this far. But neither has he repudiated the more fantastic claims by Vatican officials. And in fairness to Archbishop Martino, the catechism's argument against the death penalty does anticipate some arguments against modern war--e.g., that other avenues are available, or that the costs have become inherently disproportionate to whatever good end we hope to achieve.