Maybe it started, when the USA became the global power in the half of the 20th century and it stopped when they lost being the free and aspiring country others countries think they should model after, which might be in 2001, or when they openly started extorting their (former) allies, which is under Trump.

Well, in the 90s there was almost total adoration of the US in Russia and America meant only one thing - the US.

Decade later the US lost most of its soft power due to the abuse of its dominant military and economic position in the world and then lost its dominant position too with the rise of the economies around the world.

People now see the US as a strong state on the lands of native Americans on the continent called North America.