When the United States wanted to isolate countries like Cuba or Iran they threw all their weight[*] behind it and they alone managed to severely affect their economies. In the case of the Russian Federation instead they left to the European countries the task to define the scale of the sanctions and it resulted in a toothless opposition to the invasion of Ukraine.
Furthermore absolutely no pressure was put on Asian and African countries to at least limit their trade with the Russian Federation.
Why they did not push the sanctions against the Russian Federation in an effective manner as they did in the past with other countries? Did they eventually leave the European countries in the foreground to take the blame?
[*] By throwing their weight I mean that:
They ordered all the foreign banks with a branch in the US to comply US laws and imposed huge fines to some of the biggest European banks for breaching US sanctions against Iran.
They ordered all the foreign banks with a branch in the US to report as suspect any money transaction with countries on the list of sponsors of terrorism, given the past experience with US fines this action ended up excluding countries like Cuba from the international banking system even without needing an exclusion from SWIFT.
They threatened the executives of foreign companies under the terms of the Helms-Burton forcing them to cancel their investments in Cuba.
Also in the case of Iran they put pressure on all the foreign corporation with some business in the US to cut Iran trade. For an example search the internet with the keywords airbus cancel iran order