Going back a few centuries, the papacy started many wars. Even had its own army. I cannot think of a war any Pope has stopped.
In the modern period, the word I would use to describe the papacy is "ineffectual"
In the 20th century, the papacy was ineffectual in discouraging the German Nazis and the Italian Fascists. Pius XII lobbied world leaders to avoid war but failed.
In the Gaza war, the Pope's calls for a ceasefire and hostage release, combined with criticism of Israel, have sparked controversy and zero result. Similarly, his stance on Ukraine sometimes frustrated Catholic leadership there, notably when he appeared reluctant to directly condemn Russian aggression. Ineffectual.