Over 1,400 died in a 2013 chemical weapons attack in Syria. Trump wanted to do nothing.

In a press conference Wednesday, President Donald Trump said Monday's chemical weapons attack in Syria convinced him something must be done about Bashar al-Assad's regime. But Trump had a very different response to a 2013 chemical weapons attack perpetrated by Assad on a much larger scale.

During the 2016 presidential election, Trump repeatedly argued the United States should stop focusing on Assad and instead turn its attention to ISIS. Asked Wednesday in the White House's Rose Garden if he still held the same position, Trump responded, "That attack on children yesterday had a big impact on me." 

Trump then told reporters, "My attitude toward Syria and Assad has changed very much."

It was a rare moment of candor for a man who spent five years questioning former President Barack Obama's birthplace even after being shown Obama's birth certificate. But Trump's new stance raises a more specific question: What changed?

According to some reports, the death toll for Monday's chemical weapons attack has risen to at least 72, including 20 children. By contrast, the chemical weapons attack allegedly carried out by the Assad regime in August 2013 took the lives of more than 1,400 people, many of them children, according to U.S. estimates.

Less than two weeks after that attack, a Twitter user asked Trump what he would do if he were president. Trump replied with a harsh "America First" take: "I'd let them all fight with each other — focus on U.S.!"

Since that 2013 attack, Trump has taken all manner of positions on Assad and Syria's government. In a 2016 debate, Trump gave Assad faint praise — "I don't like Assad at all, but Assad is killing ISIS." About a week later, Trump said the Syrian dictator was "much tougher and much smarter" than Obama or his presidential rival, Hillary Clinton.

It's still unclear what Trump plans to do about the latest Syria attack, but based on his comments during the press conference, it seems he's at least considering some type of response toward the tragedy.

April 5, 2017, 6:16 p.m.: This story has been updated.