A UK Parliament report chaired by respected historian Lord Andrew Roberts calls the Oct. 7 Hamas attack in Israel deliberate and brutal, urging democracies to combat denial and misinformation.

This is what Hamas and its supporters, both in Gaza and the West, are celebrating when they deface pictures of a 9-month-old baby taken into darkness and beaten and murdered in cold blood.

Most protests have been small, but they represent the boldest challenge to the group’s authority by Palestinians since the ...