Syrian President Bashar al-Assad’s brutal dictatorship has been caught using illegal chemical weapons again.

The Trump administration has charged that the Assad regime was behind a toxic gas attack on Tuesday in the rebel-held town of Khan Sheikhoun in northwestern Syria.

The death toll rose to 72 by Wednesday, including 20 children and 17 women. Videos from the scene showed victims convulsing, choking, and foaming from the mouth, symptoms often manifested by victims of nerve gas attacks.

A sarin gas attack launched by the Assad regime in August 2013 near Damascus killed more than 1,400 people and led President Barack Obama to declare that Assad had violated the “red line” that he had set against the use of chemical weapons.

But the Obama administration backed off after then-Secretary of State John Kerry brokered a last-minute deal with Moscow that called for the destruction of Assad’s chemical weapons stocks.

It has long been clear that the Obama administration accepted that face-saving deal proffered by Russia at a high cost to its own credibility and to U.S. national interests. Assad continued using chemical weapons with impunity. The United Nations and the Organization for the Prohibition of Chemical Weapons found that Syria’s government was responsible for at least three chlorine gas attacks in 2014 and 2015.

In January 2016, the same organization reported that blood samples extracted from victims of one attack indicated they had been exposed to a sarin or sarin-like nerve toxin.

President Donald Trump on Tuesday condemned the attack in a statement:

Today’s chemical attack in Syria against innocent people, including women and children, is reprehensible and cannot be ignored by the civilized world. These heinous actions by the Bashar al-Assad regime are a consequence of the past administration’s weakness and irresolution. President Obama said in 2012 that he would establish a “red line” against the use of chemical weapons and then did nothing. The United States stands with our allies across the globe to condemn this intolerable attack. 

This statement is correct as far as it went, but the United States must do more than just condemn the attacks. It must drive up the diplomatic, political, economic, and potential military costs to the Assad regime of using illegal chemical weapons.

This means conducting a thorough investigation of the matter and holding regime officials accountable for any confirmed war crimes. Sanctions should be ratcheted up on the regime to penalize its unacceptable behavior.

>>> How President Trump Can Improve US Syria Policy

Russia has vetoed seven U.N. Security Council resolutions calling for action against the Syrian regime, so the sanctions may need to be devised and applied outside the U.N. framework if Moscow again protects its odious client regime from the consequences of its crimes.

Russia’s diplomatic credibility, which has steadily declined under the duplicitous President Vladimir Putin, has been further undermined by the failure of the 2013 chemical weapons disarmament agreement that Moscow brokered.

Washington should balk at any further diplomatic understandings with Putin on Syria, until he has taken effective action to address the violations of the 2013 agreement. The Trump administration should not repeat its predecessor’s mistake of trusting Russia to enforce agreements.

The Trump administration appropriately has prioritized the military defeat of the Islamic State, also known as ISIS, as its highest immediate priority in Syria. But reaching a political settlement to end the civil war and preventing ISIS from resurging are likely to be unreachable goals as long as Assad clings to power.

Although Assad’s departure does not need to be a short-term U.S. priority, it should be a long-term diplomatic priority if the administration expects to defeat ISIS, prevent it from making a comeback, reduce the carnage in Syria, and enable the return of more than 5 million Syrian refugees.

The Trump administration is unlikely to take direct military action against the Assad regime for its chemical attack, just as the Obama administration opted not to retaliate for repeated chemical attacks in 2014-2015.

The potential costs and risks of a direct military response are much higher after Russia’s September 2015 military intervention in Syria.

But the Trump administration can indirectly raise the military costs of Assad’s continued chemical aggression by providing greater aid to select Syrian rebel groups, who have no links to ISIS, al-Qaeda, and other Islamist terrorists or to the Kurdistan Workers’ Party.

The latest chemical attack launched by Assad’s ruthless regime is a reminder that if the Trump administration seeks to eradicate terrorism in Syria, then it cannot ignore the Syrian tyrant, who repeatedly has unleashed one of the most terrifying weapons against his own people.

For more on this topic:

Obama Administration Once Again Concedes to Putin in Syria

Time for the Obama Administration to Respond to Syrian Chemical Attacks

The Obama Administration’s Syria Policy Meltdown

Framework for Removing Syrian Chemical Weapons: Reasons for Skepticism

Obama’s Ad Lib Syria Policy Puts Putin in Driver’s Seat

Syrian WMD: Counter-proliferation Contingency Planning Needed