They signed when they were weak. That's Great Power Politics. The USA was sole Hegemon. It could do whatever it wanted. The West continued to provoke Russia because the West knew Russia was too weak to do anything about it. The West's arrogance was in underestimating how Russia would react as they continued to provoke them. (By "provoke" I mean doing things that the West knew that the Russians wouldn't like). The neocons in Washington were quite happy to see Russia invade Ukraine. They thought it was Afghanistan 2.0 (Soviet invasion, I'm referring too). The neocons thought they could bleed Russia dry using Ukraine as a proxy to bring down the Putin regime. A huge miscalculation. Now Russia and China a friends. In Great Power Politics that is a huge blunder. Why do you think Nixon, a staunch anti-communist, would do a deal with China? Answer is: Great Power Politics.

From a purely realpolitik standpoint, this war is going very well for the US. Russia is bogged down in a stalemate, with 100,000 soldiers dead already. (vs 10,000 over 10 years in Afghanistan). They've destroyed the idea that Russia is the second-strongest army in the world. NATO is now stronger and larger than ever, and haven't taken a single casualty.

My heart goes out to the Ukrainians, who are fighting determinedly not to be liquidated by Putin's mafia state. But the Dick Cheneys of the world couldn't be happier that Putin decided to invade.