I still question your claims of cause and effect here. The US abandoned this well before the USSR had fallen, and the reason the rest of Europe followed suit was not the fall of the USSR, but merely because they were blindly following the US, which they saw as a leader in this matter.

But plenty of countries did not follow down that part. There's no reason to assume this can't be stable, but you do need to limit the influence of big money and neoliberalism on your society.