US is a hegemony and the strongest nation in every respect. Who would dare slap sanctions on US without being retaliated upon? Consider the Nord Stream[1] for instance - Russians and Germans want it, US does not want it so Nord Stream is dead in the water (literally in this case).

There is not a nation on this planet that could so much as think of sanctioning US and come out ahead.

1 - https://en.wikipedia.org/wiki/Nord_Stream

That would take the USD falling from world currency reserve status - which would be the end of modern finance. That kind of economic collapse would make sanctions irrelevant.

Absolutely, the world should not tolerate aggression or deceitfulness like that from any country. Oh, I nearly forgot about Russia's polonium poisoning in the UK, and the massive state-funded doping program for the 2014 Sochi Winter Olympics where the majority of Russian athletes were doped. It really does feel like the past 7 years, Putin has really been testing the limits of what he can get away with, and sadly the answer so far is "as much backstabbing as he wants". Time for that to change