On Friday, Russia killed a United Nations-led investigation into Syria’s use of chemical weapons against its people.

Vetoing the extension of the Joint Investigative Mechanism — which has been investigating suspected chemical attacks in Syria — Russia affirmed its support for Bashar Assad's war crimes. This is the 11th time Russia has shielded Assad with a veto since 2011.

That said, we shouldn’t shrug our shoulders here.

By concealing a dictator’s grotesque violence against innocent civilians, Putin illuminates the zero-sum brutality at the heart of his foreign policy. While the Russian leader claims to seek a respectful balance of power in the Middle East and across the world, his actions prove a very different agenda.

The U.S. must respond to this challenge to international order.

First, eloquent and skilled U.S. Ambassador to the U.N. Nikki Haley should draw public attention to what Russia is doing. At the U.N. and in the full gaze of the world, the Russian ambassador should be asked to justify why his government is willing to cover up the indiscriminate gassing of Syrian civilians. Haley should follow Adlai Stevenson’s example and point to both photographic and technical evidence of what Chlorine and Sarin do to a human body.

Haley should note that weaponized chlorine gas causes "respiratory failure, pulmonary edema, likely acute pulmonary hypertension, cardiomegaly, pulmonary vascular congestion, acute burns of the upper and especially the proximal lower airways, and death."

Haley should note that weaponized sarin gas causes systemic convulsions, loss of bodily control and suffocation.

Second, President Trump should personally condemn the Russian veto. Doing so wouldn’t simply evidence American moral leadership on an issue of major humanitarian concern, it would show that the U.S. continues to regard the use of chemical weapons with the utmost seriousness.

It would also prove that the American president can challenge Putin on matters of grave consequence.

When it comes to Assad's chemical atrocities, Putin must not get a pass.