The showdown over chemical weapons in Syria has moved from the debating chambers of the United Nation to the realms of reality. President Trump is threatening missile strikes against Syria’s Assad regime. Russia, entrenched in Syria in support of President Bashar Assad, is threatening to strike back.

That might sound more terrifying than the usual default to the diplomatic exchanges at the UN, where in response to reports of dozens killed by chemical weapons this past Saturday in the Syrian town of Douma, Secretary-General Antonio Guterres called for unity at the Security Council and agreement on a “dedicated mechanism for accountability.” American missiles are probably not the accountability mechanism Guterres had in mind.

But for the U.S., the only responsible option by now is to forsake the procedural wrangles, diplomatic deadlocks and often perverse fictions of the UN. There is no magic solution to all the miseries that bedevil Syria, but it has become, at the very least, imperative to stop the attacks with which Syria’s Assad has for years now been engaged in the monstrous business of normalizing the use of chemical weapons.

This is not solely a matter of protecting the people of Syria from chemical attacks. There is an urgent need to protect the world from a trajectory on which predatory and rogue regimes are emboldened to break the longstanding taboo on chemical weapons. Last month’s attack with Russia’s Novichok nerve agent on former Russian spy Sergei Skripal and his daughter, in the British town of Salisbury, comes to mind. So does North Korea’s assassination last year of Kim Jong Un’s half-brother, hit with VX nerve agent in a Malaysian airport.

In Syria, the grim reports out of Douma are the latest in a long series of signs that the regime continues to use chemical weapons. Just this February, the U.S. State Department put out a press release expressing “grave alarm” over “continued allegations of the use of chlorine gas by the Syrian regime to terrorize innocent civilians,” noting six such instances over the previous 30 days.

The UN has had its chance, many times over, to try to stop this. Not only has it failed abysmally, but in the course of failing it has effectively provided diplomatic cover for Syria’s Assad regime and its backers in Moscow and Tehran.

This week, the UN failed yet again. The UN Security Council met on Monday and Tuesday to debate the reports of chemical weapons used in Douma, and to vote on dueling U.S. and Russian resolutions meant to revive a lapsed mechanism for investigating such reports. Even on this, there was no agreement. The U.S. resolution proposed an independent mechanism that would identify the perpetrators. Russia vetoed that, and countered with its own resolution, proposing an arrangement that would lend itself to shielding the Assad regime. That, too, was voted down.

The Security Council emerged deadlocked, unable to act. As U.S. Ambassador to the United Nations Nikki Haley summed it up: “Russia has trashed the credibility of the Council.”

Unfortunately, this was no anomalous event. This is how the UN works, a feature designed right into its nobly-intended but morally obtuse DNA. The world’s dictatorships routinely exploit the procedural gifts of the UN to their own advantage. Prime among this crowd, and a sordid inspiration to the rest, is Vladimir Putin’s Russia, one of the five veto-wielding permanent members of the 15-member Security Council.

No surprise then, that in Syria the UN’s role has been a debacle. The diplomatic trainwreck began soon after the 2011 uprising in Syria, when Assad responded to peaceful protests with brutal force. In August, 2011, President Obama called for Assad to step aside. But instead of putting U.S. muscle behind that proposition, Obama deflected Syria’s growing upheaval, over and over, to the UN. In 2012, the UN in tandem with the Arab League dispatched former UN Secretary-General Kofi Annan as a mediator between Assad and the Syrian opposition. This was an early salvo in what became round after round of ineffectual UN-linked diplomacy, while Syria descended into war and the death toll began its climb toward the current total of more than half a million.

In 2012, amid concerns that the Assad regime was readying chemical weapons, Obama drew a red line. In 2013, faced with horrific evidence that Assad was using these weapons, Obama erased his red line and turned over to Russia the project of ensuring the elimination of Syria’s chemical weapons. This U.S.-Russian deal was enshrined under auspices of the UN Security Council. In the half decade since, it has yielded dual disasters: failing to end Assad’s use of chemical weapons, while facilitating the entry of Russian military forces into Syria. Today, Russia is in the business of defending both diplomatically and militarily the chemical-weapons-wielding tyrant it was supposed to disarm.

So much for the good offices of the United Nations. It now falls to the U.S. and its allies to redraw the red line over chemical weapons that Obama never should have erased in deference to Russia and the UN back in 2013. That will likely require actions more definitive than the 59 cruise missiles Trump launched at a Syrian air base a year ago. Risky, yes. But Assad and his patrons must be stopped, and if America does not take the lead, who will?