The Monroe Doctrine
In 1823, President Monroe proclaimed the Monroe Doctrine: all of the Americas were for the US. The US was far too weak to keep all the Europeans out, but they did their best. Trump, of course, says the US wants Canada and Greenland to be under US control, and, if the permanent US government let him, the US could probably force Canada and Greenland to become US somethings or other (not clear exactly what Trump has in mind, or if the permanent government will go along, or what).
For 75 years after the Monroe Doctrine, the US strongly condemned colonialism and fought it in the Americas, with some success: Spain and Portugal, who had been given all of the Americas by the Pope, lost most of their mainland colonies during the 19th century.
European Colonialism
The British and the European Imperialist nations sent their military to destroy the government of a state, then they replaced the government with a government where all senior government officials had to be British- or European-born. The junior government officials who did most of the hard work were often natives of the colony, but their bosses were British- or European-born, and the resident head of state was a British- or European-born governor or viceroy, while the ultimate Head of State was the British or European Head of State.
US Neo-colonialism
The US used (and use) a combination of money and military force to not-quite-as-surreptitiously-as-they-proclaimed, install citizens of their neo-colonies as the government of the state in what is always supposed to be the 'choice' of the citizens of the neo-colony. The government and other leaders of the country were all citizens of the state, but they knew they would remain well-paid leaders only so long as did whatever the US ordered them to do.
This was fairly easy when Monroe proclaimed that the US would end European colonialism in the Americas.
When Spain and Portugal had colonies in the Americas, the senior government officials had trouble sending their wives back to Spain or Portugal, so their children were not European-born, and so could not hold the most senior offices, and strongly resented the fact. The US found it very easy to support revolutions throughout Latin America, providing the American-born pure-European-blood Latin Americans with lots of money and weapons with which they managed to evict Portugal from Brazil and Spain from most of the rest of Latin America, and then those pure-blood-Europeans, who were American born, replaced the Spanish- and Portuguese-born rulers, with a lot of help from the US in the form of money and weapons and maybe US military help.
The US military ensured that the new governments of 'independent' Latin American countries knew that their lofty, well-paid positions depended on keeping the Americans happy, so the US got all the bananas and sugar and other valuable minerals, the indigenous Americans, Africans, and mixed-bloods did all the work of growing the coffee, bananas, and mining the minerals and loading it all on boats to be shipped to the US for almost no pay, so the Americans who owned the banana and sugar and mineral corporations and the leadership of the countries were all happy.
The pure-European blood who became the neocolonial leaders of the country were very well paid and lived in beautiful villas with lots of cheap servants, while the pureblood indigenous Americans and Africans and mixed-blood citizens were stuck in abject poverty, living in houses they put together from the jungle leaves with no electricity or running water (well, no indoor running water, they had the streams in their country they could use for bathing and drinking water).
After WWII, the two Great Powers were the US and the USSR, and they divided the world, with the USSR neo-colonising the Warsaw Pact and the US neo-colonising the other NATO nations.
But then, in 1949, the PRC threw out the neocolonial powers and became truly independent (and impecunious). The US wanted to return the entire PRC to a neo-colony of the US, but only got Taiwan, and even there, the US had to accept 'strategic ambiguity': the US must say that Taiwan is just another province of the PRC while acting like Taiwan is a US neo-colony, with an ambassador (who cannot use the name ambassador) and an Embassy in D.C. (that must never be called an Embassy).
The USSR tried to help the PRC, but then International boundaries, all drawn by the Europeans, got in the way, with the USSR saying the boundaries were drawn too far north and the PRC saying those boundaries were drawn too far south. So relations between the PRC and the USSR became very strained.
Then the PRC ping-pong team invited the US ping-pong team to the PRC, and from there, the Nixon government agreed to recognise the PRC and started moving American factories from the US, where labour was expensive, to the PRC where labour was almost free (by American standards).
So the US built lots of factories in the PRC and the Americans who built those factories made huge profits. But the PRC saw and learned and started building PRC factories over the next 50 years. The PRC now has the most cars. One sees GM cars and Ford cars built in the PRC, but also BYD cars and other brands with names in Chinese characters, copied from the US/German/French/Japanese/Korean factories.
And the US are desperate to make Russia and the PRC into US neo-colonies, as both obviously should be, but the US have no idea how to do this.