[fancifalmanima]

If you look at what was actually agreed to, it seems like the US and EU are already doing more than obligated. I don't see any nuclear weapons being used, the west has respected their sovereignty, and is even economically sanctioning Russia and providing intelligence and equipment. Bringing this to the security council would do nothing anyways, as Russia is a part of it and any resolution would just get vetoed. The only party that's actually breached the agreement is Russia.

    Respect Belarusian, Kazakh and Ukrainian independence and sovereignty in the existing borders.[17]
    Refrain from the threat or the use of force against Belarus, Kazakhstan and Ukraine.
    Refrain from using economic pressure on Belarus, Kazakhstan and Ukraine to influence their politics.
    Seek immediate Security Council action to provide assistance to Belarus, Kazakhstan and Ukraine if they "should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used".
    Refrain from the use of nuclear arms against Belarus, Kazakhstan and Ukraine.
    Consult with one another if questions arise regarding those commitments.[13][18]