New York ( CNN ) -- President Barack Obama 's policy toward Syria -- three years of red lines and calls for regime change -- culminated Monday in a barrage of airstrikes on terror targets there , marking a turning point for the conflict and thrusting the President further into it . The U.S. said Saudi Arabia , the United Arab Emirates , Qatar , Bahrain and Jordan had joined in the attack on ISIS targets near Raqqa in Syria . The U.S. also launched airstrikes against another terrorist organization , the Khorasan Group . Obama described its members as `` seasoned al Qaeda operatives in Syria , '' and U.S. officials said the group was plotting attacks against the United States and other Western targets . Initially hesitant to become involved in the Syrian conflict , which pits an authoritarian regime led by President Bashar al-Assad against a patchwork of rebel groups , Obama has moved from sending weapons to opposition fighters last year , to backing away from airstrikes against al-Assad , to ordering Monday¹s campaign to take out ISIS terrorists who have used the Syrian unrest to gain a foothold . Airstrikes : What you need to know . It¹s new ground for the U.S. , which lacks robust intelligence capabilities in Syria and has n't sent any ground forces there . Unlike the campaign against ISIS in Iraq , the U.S. doesn¹t have al-Assad¹s permission to launch airstrikes in Syria , though the U.S. notified him before the attacks began . The coalition strikes began the evening before Obama made his annual visit to the United Nations General Assembly , where the White House hopes to secure broader support for the anti-ISIS campaign from a range of allies . The main focus , officials say , is on stemming the flow of foreign-born fighters who have joined up with ISIS and other terror groups in Syria and Iraq . The U.S. intelligence community believes there are 15,000 foreign fighters from 80 countries who are fighting alongside ISIS and other similar terror groups -- 2,000 from Europe and roughly 100 from the United States . A senior administration official said on Monday that some of those Americans had already returned to the United States and were being tracked by the FBI . Not all of those who have returned were fighting for ISIS . Most positive reaction to Syria airstrikes comes from Obama 's critics . Administration officials are confident in the prospects of a U.S.-backed resolution that would compel nations to try to stop citizens from leaving to fight for terror groups . Obama will personally chair a session of the U.N. Security Council on Wednesday to push for the measure . He last chaired the panel in 2009 , and was the first American president to do so . Here is a timeline of the major events leading up to U.S. action in Syria : . • August 2012 : President Obama lays out a `` red line '' in the Syrian conflict , saying that the use of chemical weapons would `` change his calculus '' on Syria . • March , April , June 2013 : The Syrian government uses chemical weapons against opposition forces in Syria . • August 2013 : The al-Assad regime continues to use chemical weapons and Obama lays out a plan for limited military intervention against the Syrian regime while asking Congress to weigh in . • September 2013 : Congress is reticent to endorse U.S. military action in Syria . But then , in a plan engineered by Russia , al-Assad agrees to give up Syria 's chemical weapons and Obama begins to back away from military strikes . • June 2014 : Obama sends more than 300 military advisers to Iraq to advise Iraqi forces and protect U.S. interests . • July 2014 : Obama sends more advisers to Iraq . • August 7 , 2014 : Obama authorizes targeted airstrikes in Iraq to guard American interests and protect minorities facing impending massacre by ISIS militants . • August 20 , 2014 : American journalist James Foley is beheaded by ISIS . The video is posted online . Within the next few weeks , ISIS beheads another American journalist , Steven Sotloff , and a British aid worker , David Haines , and posts those videos online as well . • September 10 , 2014 : Obama announces he 's authorized the U.S. military to strike ISIS in Iraq and Syria . In addition , he announces a plan to arm and train 5,000 moderate Syrian rebels , pending congressional approval . • September 18 , 2014 : Congress approves the President 's plan to arm and train Syrian rebels . • September 22 , 2014 : The U.S. launches its first airstrikes in Syria in coordination with five Arab nations . Maps : Arab nations join U.S. , expand fight against terror to Syria .
Saudi Arabia , UAE , Qatar , Bahrain and Jordan joined in the attack on ISIS targets . Obama has moved from reluctance to launch airstrikes to ordering Monday¹s campaign . Coalition strikes began the evening before Obama visits U.N. General Assembly . Focus is on stemming the flow of foreign-born fighters who join up with ISIS , other groups .