It doesn't pay to be a litter bug - even in space.
Humans are such slobs ... .
We need to send the "Quark" to clean up the mess.
I don't know what the current stats are, but at one time the Soviet Union was responsible for 90% of the mass in space and 99% of the debris. Soviets launch heavy and dirty.
I'm still more'n a wee bit skeptical that we could ever acheive "critical mass". Space is big, radiation pressure and residual drag effect smaller stuff more. The issue is probability of a spacecraft being damaged by debris prior to its "natural" age. I think the number of satellites that have died in that fashion is exactly 0. I suspect that if space becomes a couple of hundred times dirtier, the mortality rate of satellites might tick up 0.1% or so.
This may just be a backdoor way of trying to stop missile testing by the U.S., now that we are at the threshold of widescale capabilities, ahead of the rest of the world.