Trump pledges retaliation after 3 Americans killed in Syria ISIS attack

• President Trump vowed "very serious retaliation" after an ISIS attack in Syria killed two US service members and one American civilian.
• The attack, which also wounded three US service members, occurred in central Syria and is blamed on the Islamic State group.
• The two deceased service members were identified as members of the Iowa National Guard.
• This incident marks the first fatal attack on US troops in Syria since the fall of President Bashar Assad a year ago.
• Syrian officials suggested the lone gunman, who was killed, might have been a member of their Internal Security force with extreme ideology.

Why It Matters: US deaths in Syria prompt Trump's retaliation, signaling renewed ISIS threat and instability.