polls and payment refusal by USA government?

why do the USA insist on taking advantage on refusing to pay congestion charges when everybody else in USA ( visitors has to pay their tolls)? 3/4 of all embassies pay it and it's not as if they cannot afford it (hardly Zimbabwe is it) Is it simply they wont pay as they do not regard us as worth taking any notice of? I am sure they would pay Saudi Arabia any congestion charges. maybe we should tax all our visitors going to USA a £1 a head to make up for it with the charge clearly stated as a default payment for and on behalf of USA government who insist on not paying lawful charges in a host country. ps I am told they also routinely ignore parking fines etc. so much for obeying a host countries laws!