Newly minted Secretary of Defense James Mattis celebrated his first full day at the Pentagon by overseeing 31 strikes against the Islamic State in Iraq and Syria. Mattis entered the Pentagon Saturday with a smile for his first full day of work, and for good reason, considering the significant bombardment ISIS forces received. A variety of fighters, bombers and remotely piloted aircraft engaged in the bombing run, which saw 25 strikes in Syria and six in Iraq. In Syria, two strikes destroyed ISIS units and artillery near the town of Bab. ISIS forces in Raqqa, the terrorist group’s de facto capital,...