Complex sentence: Chemical weapons were used in the August 21,2013 Ghouta attacks, according to the UN, the United States and other Western countries blamed the Syrian government for the attack, while Syria has blamed rebels.
Split into simpler sentences: Chemical weapons were used in the August 21,2013 Ghouta attacks, according to the UN. The United States and other Western countries blamed the Syrian government for the attack, while Syria has blamed rebels.