Russia and China have no interest in increasing the power of the UN; they want to increase their own power relative to other nations, and in this particular case they think that the UN will be a useful channel to do so.
In other situations Russia and China fight to reduce the power of the UN. Mostly situations where western powers are seeking UN legitimacy for piercing national sovereignty, such as in the run-up to the U.S. invasion of Iraq. Today Russia opposed UN intervention in Syria, and I think China does as well.
In other situations Russia and China fight to reduce the power of the UN. Mostly situations where western powers are seeking UN legitimacy for piercing national sovereignty, such as in the run-up to the U.S. invasion of Iraq. Today Russia opposed UN intervention in Syria, and I think China does as well.