The United States would once more push for Syrian leader Bashar al-Assad to step down from power following the Chemical Attack in Idlib province. The use of sarin gas by Syrian soldiers on Tuesday resulted in the death of 73 people, including 23 children. It is considered the worst chemical attack in Syria in four years.

Crossing the line

U.S. President Donald Trump called the attack as an affront to humanity. He pointed out that Bashar al-Assad had crossed the line so many times, and it is the responsibility of the U.S. to act now and stop the carnage, The Telegraph reported.

He described the chemical attack in Syria against women and small children, including “beautiful little babies” and their death, as so horrific. “These heinous acts by the Assad regime cannot be tolerated. The US stands with our allies across the globe to condemn this horrific attack,” Trump said at a White House press conference.

Fighting with Russia

In the Syrian civil war, the U.S. has Russia as an ally as both nations are supporting the Kurdish People’s Protection Units. American military commanders said that troops from Russia and the U.S. are within “hand-grenade” range of each other in some parts of Syria.

Although the U.S. Defense Department stopped in 2014 military-to-military cooperation with Russia since the annexation of Crimea that year, Pentagon is setting aside its differences with Moscow.

The reason behind the cooperation is both countries want to defeat ISIS which recently called Trump an idiot.

Partly blames Obama

While Trump said his attitude toward Assad and Syria has changed very much because what happened on Tuesday is so unacceptable, the president also partly blamed the incident on his predecessor, former U.S.

President Barack Obama. He said Obama promised in 2012 to establish a “red line” against the use of chemical weapons, but Trump claimed the former president did nothing.

However, Joe Scarborough, co-host of “Morning Joe,” a show on MSNBC, said on Wednesday that Trump hitting Obama for his predecessor’s failures is unbecoming.

Scarborough said that Trump cannot criticize Obama and “then allow it to happen in 2017 and do absolutely nothing while this holocaust unfurls before our eyes.”

In 2013, the U.S was about to launch air strikes in Syria after a chemical attack on suburbs in Damascus that killed more than 1,300 people. However, Obama did not push through with the air strikes because Congress voted against intervening in the civil war.