Some people wanted a multi-polar world, well, this is what a multi-polar world looks like: the poles start competing, including arms races. "History may not repeat itself but it often rhymes." as they say.
>Some people wanted a multi-polar world
Specifically, the people who are not part of the American mono-pole.
Any world configuration that consists of large groupings of fear driven people(nations, etc) will includes nukes. That is the world we live in. Unipolar, bipolar, multipolar, makes no difference.
The only thing that matters is that all people rise up and demand an end to nuclear weapons.
going to need to spend a lot more money than currently to support that...
Perhaps we didn't realize how much stability the "two powers" model generated. It caused inevitable arms races as the two powers vied to stay competitive, but there were only two. And the USSR was able to de-escalate on its own. If you have three powers, each of them wants the ability to eliminate not one, but both of the others. Could lead to not just incremental, but polynomial expansion of forces. And de-escalation involves multiple parties coordinating, not just one great power.