Israel struck the headquarters of Hamas’ political leadership in Qatar on Tuesday as the group’s top figures gathered to consider a US proposal for a ceasefire in the Gaza Strip. The strike on the territory of a US ally marked a stunning escalation and risked upending talks aimed at winding down the war and freeing hostages. The attack angered Qatar, an energy-rich Gulf nation hosting thousands of American troops that has served as a key mediator between Israel and Hamas throughout the...