This opportunity seems to be an interval point, because either it will lead to save the understanding from the failure and going on in the cooperation which was stated by the understanding between the US air defense and the Russian one in the war on ISIS and Al Nusra front, along with a stable truce between the Syrian army and its allies on one hand, and the formations of the opposition affiliated within the political process, that are separated from the sites and the formations of Al Nusra and ISIS on the other hand.
Meantime, opening the way for the arrival of the relief convoys to different areas, or the collapse of this understanding, at least for not a short time, where the escalation rises accompanied with confrontational positions between the two parties which are confronted internationally and regionally either in Syria or in other fronts of engagements especially Yemen and Ukraine, and the disruption of the process of liberating Al Mosul in Iraq which based on an implicit Iranian-American cooperation through supporting the Iraqi army.
Thus the opportunities of the success of the negotiation converge and diverge on the basis of the convergence and the divergence of the common reading of the risks of the failure and their threats in each negotiating item. The interests of a team are bigger than the costs which are supposed that it has to pay through what is stated by the negotiation and making the understandings. This means that the reach to any understanding through the negotiations means a convergence in estimating the balances and what will be imposed by the failure, and whenever it seems that the understanding overbalances for a party, it means that the negotiating failure will mean more losses to the other party.