Cardinal Robert McElroy used a Vigil Mass for Peace in Washington on April 11 to condemn the war with Iran as morally indefensible and to urge Catholics to pray and press for an end to the fighting. The liturgy at the Cathedral of St Matthew the Apostle formed part of the wider response to Pope Leo XIV’s call for prayer amid the conflict.

In his homily, the Archbishop of Washington said Catholic teaching left no room to justify either the outbreak of the war or its continuation. He argued that the conflict had failed the moral tests required by the just-war tradition and called on the faithful to pray that the ceasefire would hold and open the way to a more lasting peace in the Middle East.

McElroy also urged Catholics to make their concern public. At the cathedral he encouraged worshippers not only to pray for peace but also to advocate with political leaders for an end to the conflict. The service drew hundreds of people and included clergy from the Archdiocese of Washington, among them Cardinal Wilton Gregory and auxiliary bishops serving the archdiocese.

The Mass followed Pope Leo’s appeal for a global day of prayer. The Archdiocese of Washington announced the liturgy after the Pope, speaking at his April 8 general audience, welcomed a two-week ceasefire between the United States and Iran and asked Catholics to support delicate diplomatic efforts with prayer.

McElroy had already spoken publicly against the conflict before the Mass. In an April 7 statement issued by the Archdiocese of Washington, he backed the call of Archbishop Paul S. Coakley and the US bishops for an immediate halt to hostilities and warned that a nation choosing war on such terms had lost its moral compass.

The Washington vigil took place on the same day as Pope Leo’s peace vigil in Rome and reflected a broader Catholic insistence that prayer, dialogue and restraint are the only credible path forward. McElroy’s intervention placed that argument in sharply moral terms, presenting the  war not simply as a strategic failure but as one incompatible with Catholic principles.