Vice President JD Vance appeared to warn Pope Leo XIV to "be careful" when speaking about theology and U.S.'s war: "For over a thousand years, the Catholic Church has taught just war theory and it is that long tradition the Holy Father carefully references in his comments on war," Auxiliary Bishop James Massa of Brooklyn, New York, chairman of the U.S. Conference of Catholic Bishops' Committee on Doctrine, said in a statement released April 15.