In a new book, Pope Francis called for an investigation into whether Israel’s ground offensive in Gaza constitutes a genocide, sparking intense debate about the war — and also raising questions about the tangible impact that papal statements have on Catholics and global politics.

While Pope Francis has criticized the war before, this is the first time he has publicly suggested an investigation, according to excerpts from a new book.

It’s the first time that Francis has openly urged for an investigation of genocide allegations over Israel’s actions in the Gaza Strip. In September, he said Israel’s attacks in Gaza and Lebanon have been “immoral” and disproportionate, and that its military has gone beyond the rules of war.