As much as President Donald Trump says he wants to pull U.S. troops out of Syria and let others worry about the civil war there, Syrian President Bashar Assad is making it difficult. On Saturday night, Syrian government troops reportedly launch a poison gas attack on the rebel-held town of Douma, near the Syrian capital. Over 40 people died of suffocation, including whole families in their homes.

This is the kind of violation of human rights and international law that led to the overthrow of Saddam Hussein in Iraq. Any despot who uses chemical weapons against his own people to cling to his dictatorship needs to be brought to justice for war crimes.

Trump, who has talked about pulling troops out of Syria “very soon,” was outraged at the report, tweeting Sunday that Assad was an “animal” and even criticized Russian President Vladimir Putin, Assad’s ally, for supporting Assad’s government. Trump said there would be “a big price to pay.” That may include cruise missile strikes, which the White House said is not off the table.

Putin should learn that a person is known by the company he keeps. He and Assad will be lumped together for this atrocity.