How much money and resources do you have at your disposal?.
Personally, not much compared to the problem.
How much did Cassini cost? This sounds like that level of importance.
Getting rid of the BIG objects that are at risk of being broken up into smaller objects makes sense to me. But do we make small satellites where multiples can be put into one launch and each small satellite pulls something out of orbit in a kamakaze mission, or do we use a large satellite that can refuel at the ISS and used again and again. The US could remove its own garbage to prove the concept then bill other countries to pull their stuff down.