How Trump, Obama Responded When Chemical Weapons Were Used

Russia's alleged use of chemical weapons in Ukraine threatens to change the international response to the war—and it's not the first time U.S. presidents have dealt with the use of the weapons.

On Monday, a Ukrainian battalion accused Russia of using chemical weapons against Ukraine's military and civilians, marking a potentially significant escalation in the conflict as world leaders pledged a strong response if Russia were to use the weapons.

Chemical weapons use commercial, toxic chemicals to cause illness or death to their targets, and their use is widely condemned in the international community. In fact, the use of chemical weapons is considered a breach of war conduct under the Geneva Protocol, which banned chemical and biological weapons.

Despite being banned, some countries have continued to use chemical weapons during conflicts into the present day, with their use typically striking a strong response from other countries. Notably, Syrian President Bashar al-Assad has faced accusations of using chemical weapons on his own people.

Both former Presidents Barack Obama and Donald Trump responded to the use of chemical weapons in Syria during their presidencies.

In 2017, after Assad's troops allegedly carried out a chemical weapons attack over the town of Khan Sheikhoun—killing at least 86 people, 20 of whom were children—the Trump administration authorized 59 missiles to strike a key Syrian airfield near Homs.

Trump—along with the United Kingdom and France—again launched strikes on Syria in April 2018 for another suspected chemical weapons attack. He said at the time the U.S. was "prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents."

In 2013, after an alleged chemical attack, Obama asked Congress to authorize military intervention but found little support. Instead, the United States removed more than 1,300 tons of chemical agents from Syria. He ordered airstrikes in Syria as part of a military campaign against ISIS in 2014.

Obama's more restrained response was criticized by Trump and other Republicans. Trump wrote in 2018 that "if President Obama had crossed his stated Red Line In The Sand, the Syrian disaster would have ended long ago!"

Obama defended his response in a 2017 interview with Medium, noting his decision not to bomb Syria over the weapons was "the issue that required the most political courage."

"Now, we know subsequently that some remained, so it was an imperfect solution. But what we also know is that 99 percent of huge chemical weapons stockpiled were removed without having to fire a shot," he said.

The Biden administration, meanwhile, has threatened aggressive action if Russia uses chemical weapons. Linda Thomas-Greenfield, the U.S. ambassador to the United Nations, warned in March that "if they escalate to this level, we will respond aggressively to what they are doing."

"You've seen the consequences so far of our actions against Russia and against Putin, and they are feeling those consequences, and they will feel more if they take this unfortunate decision to use chemical weapons," she said.