Reports on Tuesday revealed Syrian President Bashar al-Assad and his allies again targeted civilians in a deadly attack where chemical weapons were used. The attack was one of the worst chemical attacks in the six-year Syrian civil war.

Rewind back to the fall of 2013, when the Obama administration was working with Syrian and Russian leaders to ensure that Assad's stockpile of chemical weapons would be turned over and destroyed. A deal was reached, and the Obama administration and fellow Democrats applauded the achievement. The agreement was struck a year after former President Barack Obama drew his now infamous "red line" in August 2012, when he threatened military action against Assad if he used chemical weapons.

For several years, Democratic lawmakers and Obama administration officials touted that Syria turned over "100 percent" of its chemical weapon stockpile.

"It turns out we are getting chemical weapons out of Syria without initiating a strike," Obama said.

"We struck a deal where we got a hundred percent of the chemical weapons out," then-Secretary of State John Kerry said.

The Obama White House even tweeted out a statement promoting its achievement.

President Obama on eliminating the Syrian regime's "most lethal declared chemical weapons" → http://t.co/Ny4mp8oHdk pic.twitter.com/nqbyTeKfSF — White House Archived (@ObamaWhiteHouse) August 18, 2014

In May 2015, Bloomberg reported that Assad used chemical weapons after the Obama administration declared Syria had turned over its entire stockpile. Obama dismissed the report and said chlorine is not "historically" considered a chemical weapon–despite chlorine gas being one of the world's first chemicals weaponized for modern warfare.

After the report, Obama administration officials continued to say that Syria turned over all of its chemical weapons.

Then-White House Press Secretary Josh Earnest went on MSNBC's "Morning Joe" and said four times that Assad did not have a chemical weapons stockpile.

"Right now, Bashar al-Assad doesn't have a declared chemical weapon stockpile," Earnest said in September 2015.

Before leaving office, Obama was asked in a "60 Minutes" interview if he would have done things differently when it came to Syria.

"Would you take it back?" Steve Kroft asked Obama, referring to the red-line comment.

"I would have, I think, made a bigger mistake if I had said, ‘Eh, chemical weapons. That doesn't really change my calculus.' I think it was important for me as president of the United States to send a message that in fact there is something different about chemical weapons," Obama said. "And, regardless of how it ended up playing, I think–in the Beltway, what is true is Assad got rid of his chemical weapons."