The leaders of eight of the world’s largest national economies have just finished meeting in Northern Ireland for the annual G8 Summit. This year’s summit was largely characterized by the isolation imposed on Russian Prime Minister Vladimir Putin by the other heads of state over differences on the Syrian crisis, prompting Canadian Prime Minster Stephen Harper to dub the event as the “G7 plus one.” Personal tension between Putin and President Obama was on display as the world observed their icy body language and unfriendly dispositions while they awkwardly sat on stage together.

What’s the point of an international conference like the G8 when its participants are unable to pressure Vladimir Putin, who proudly arms and supports mass murder Bashar al-Assad? This is a man whose loyalist thugs are shooting children in the face on a daily basis and who has already killed, according to the UN, a hundred thousand people with the aid of chemical weapons. Yet Putin’s endorsement of the Assad administration is still bold and unwavering. It’s a travesty that Russia was invited to the G8 summit, especially as Putin shamelessly disregards the pleas of the international community to withdraw his support from the criminal regime. This summit is meant to facilitate the collaboration between civilized nations for a better future. If we can’t stop the ongoing slaughter or, at least, bar Russia’s participation from the summit until they change their policy, then the forum becomes guilty of passive complicity.

Condemnation of mass murder in Syria on the part of the West has not abated the slaughter in the slightest. But welcoming Putin to an international conference while he stubbornly refuses to stop arming Assad as he decimates his people is simply too much.

I’ve been a vocal supporter of President Obama’s selection of Samantha Power as the U.S. ambassador to the United Nations, dissenting from most of my other pro-Israel colleagues who have opposed her appointment. I know Samantha personally, and the principal reason I support her is because she’s the foremost anti-genocide voice in the world. I am grateful to her for all she has done to give voice to the millions who were slaughtered in twentieth century genocides while the world looked the other way. I trust that in her new position she will do everything she can to end the violence in Syria through relentless denunciations of the bloody Assad regime.

But until her appointment is confirmed, it is President Obama himself who should be going to the UN and giving a speech along these lines:

“Friends, as we sit here innocent Arab children in Syria are being slaughtered from the air by planes and helicopters, and murdered in their homes with guns shot at point blank range. President Bashar Assad is a tyrant who will hold on to power at all costs.

“As the President of the United States I am here today to tell Mr. Assad – I will not call him President because any man who slaughters who is own people has lost all legitimacy to rule – that my nation regards him as a war criminal responsible for crimes against humanity. I am urging the United Nations to immediately pass a resolution proclaiming the same.

“My country is right now engaged in a difficult war in Afghanistan. Still, we have decided, now that we have confirmed that Assad has used chemical weapons against his own people, to arm the rebels in their fight. And while we may not be able to act directly against Mr. Assad in the short term, I want him to know that the long arm of American and international justice will find him, arrest him, and try him, providing that the vigilante justice of his own aggrieved people doesn’t catch up to him first, as it did Muammar Kaddafi in Libya. Mr. Assad will be held accountable for his crimes, either at the International Court of Justice in the Hague, or at a court in Syria.

“Mr. Assad, the eyes of the world are upon you and your dastardly deeds. You will not get away with murder. I am personally telling you today that if it’s the last thing I do as President, I will ensure that you are arrested and tried for your brutal and unspeakable crimes. When we Americans say “Never Again” we mean each and every word. We will never allow unpunished, wholesale slaughter to rule in the world ever again.”