analysis Interpretation of the news based on evidence, including data, as well as anticipating how events might unfold based on past events.

The last time the United States was faced with how to respond to a chemical attack committed by forces under Syrian President Bashar al-Assad was in 2013, when 1,400 people died from sarin rockets in Ghouta. President Barack Obama considered responding with a military strike but declined to do so after Russia offered to negotiate with Assad to remove chemical weapons from his arsenal.

Area controlled by: Assad regime Islamic State Kurdish groups Opposition groups September 2013 At the time, Syria was two-and-a-half years into a civil war between forces loyal to Assad and rebels. Aleppo Raqqa Homs 50 MILES Damascus Ghouta Site of chemical attack that killed 1,400 on Aug. 21, 2013. April 2017 Now, the conflict has morphed into multifactional war, with Islamic State and Kurdish troops also fighting within the country. Aleppo Khan Sheikhoun Known Russian military locations Site of chemical attack on April 4 that killed 80 people Area controlled by: Islamic State Kurdish groups Armed opposition groups Assad regime September 2013 Aleppo Raqqa Idlib Deir al-Zour Homs Damascus At the time, Syria was two-and-a-half years into a civil war between forces loyal to Assad and rebels. Ghouta Chemical attack that killed 1,400 on Aug. 21, 2013. April 2017 Aleppo Latakia Khan Sheikhoun Deir al-Zour Chemical attack on April 4 that killed 80 people 50 MILES Homs Known Russian military locations Now, the conflict has morphed into multifactional war, with Islamic State and Kurdish troops also fighting within the country. Damascus

Close quarters

The United States’ involvement in Syria has evolved since 2011 from providing weapons and training to rebels, to airstrikes against the Islamic State to deploying troops into the country. More than 800 U.S. ground troops are stationed in Syria, some near Russian military stations.

Kobane TURKEY Manjib Hasakah Raqqa Tabqa dam Deir al-Zour IRAQ SYRIA Qamishli TURKEY Kobane Incirlik air base Mosul Manbij Hasakah Raqqa IRAQ Aleppo Tabqa dam Med. Sea Deir al-Zour Khan Sheikhoun Latakia Palmyra Tartus Shayrat air base LEBANON Scale varies in this perspective