He's done it: Sergei Lavrov just told the U.N. Security Council that U.S. coordination with terrorist groups in Syria warrants a full, impartial investigation.

In a carefully-worded address given in New York on Wednesday, Russia's Foreign Minister cited recent "coincidences" which have undermined the cease-fire agreement in Syria — and allowed ISIS and Al-Nusra to launch successful attacks:

Lavrov didn't mince his words during his address to the Security Council Coalition strikes on government troops positions at Deir ez-Zor on September 16 is a blatant violation of the cessation of hostilities regime. Furthermore, right after those strikes, ISIS forces attacked government troops. On September 19, there was another unacceptable provocation. I am referring to the bombing of a UN humanitarian convoy near Aleppo on a territory controlled by the armed opposition. Incidentally, it should be noted that on the same day, September 19, in the same area known as the Ramus road, Jabhat al-Nusra and allied detachments mounted a fierce attack on government forces. As a result, the jihadists advanced to Neighbourhood 1070. I am not trying to make any accusations. However, I am convinced that such coincidences call for serious analysis and investigation. We insist on the most thorough and impartial probe into the attack against the humanitarian convoy. There are many indications that it could have been a rocket or artillery attack. Initially that was how it was reported. Then they started mentioning helicopters and then aircraft. Therefore it is probably necessary to refrain from emotional responses and to not immediately grab the microphone and make comments, but conduct a thorough and professional investigation.

It's difficult to overstate what Lavrov's statements will mean going forward: In the most diplomatic way possible, Lavrov just accused the United States of military coordination with ISIS and Al-Nusra. Or, at the very least, he is suggesting that the U.S. acted with full knowledge that these terrorists groups would immediately benefit.

Lavrov's comments about the changing narratives of the aid convoy attack is easily verified: As we reported yesterday, the attacks were described first as involving helicopters, then Russian air strikes were blamed, and now not even NATO's Secretary General is brave enough to speculate. Even the U.N. quickly dropped the "air strike" language after it was clear that it could not be substantiated.

The blatant bombing of Syrian army positions — coupled with the latest accusations against Moscow, without providing any evidence — makes it difficult to believe that a meaningful cease-fire agreement will ever be realized. And of course, an impartial investigation into the attack on the aid convoy will never materialize.

We are now reaching a critical stage in Syria. When Lavrov and Kerry announced on September 9 that a deal had been reached, Lavrov began his remarks with a rather ominous warning: "I have to say, the – some mistrust remains and some – there are some people who would like our – today’s arrangement to be undermined."

Will the international community finally take a stand against Washington? If not, expect more "coincidences" — with disastrous consequences.