US forces targeted facilities used by Iran-backed militants in Iraq in response to attacks on American personnel in both that country and Syria, Defense Secretary Lloyd Austin said on Tuesday. The strikes – which will add to already significant pressure for US forces to depart the country – came just days after American troops in western Iraq were targeted with ballistic missiles and rockets, an attack the Pentagon blamed on militants supported by Tehran. “US military forces conducted necessary and proportionate strikes on three facilities used by the Iranian-backed Ketaeb Hezbollah militia gr…