I love Americans...but this is what sumps up the last 3 centuries.
19th century: Monroe says that the Americas are their own business. No European can interfere.
Yes, although in fairness, most Americans didn't want to be involved in European affairs either through most of the 19th century. However, the only real major power we needed to worry about was Britain. France and Spain were weakened.
The other major foreign policy aspiration of the US at the time was "Freedom of the Seas," and this has remained so ever since. We didn't want anyone messing with our ships. Both the US and Britain saw eye-to-eye on that point, because each in our own way, the seas were our lifeline.
20th century: Europe becomes USA's business. Nobody can interfere
Starting with WW1, yes. The reason the US declared war was due to the Kaiser's declaration of unrestricted submarine warfare which would have been considered a valid pretext for war under the doctrine of "freedom of the seas." There was also the Zimmermann Note which suggested the possibility of the Germans encouraging Mexico to attack the U.S.
But after that, the US went back to its original norm of "no foreign entanglements." Some people call it "isolationism," but I think that term is a misnomer, since we still maintained amicable relations with most of the world, continued to trade, had open travel and communication with other countries - though immigration was severely restricted from 1924 until after WW2.
21th century: Africa and Middle East becomes USA's business. Nobody can interfere.
The World Wars weakened Britain and France, which caused restlessness in their empires and the chaotic situation which dominated geopolitics in the decades following WW2. A lot of colonies wanted to become independent but the West feared that the Soviets would take advantage of the power vacuum that was forming in the world.
Some might refer to continued Western hegemony in these regions as a form of "neo-colonialism" or often known as "imperialism," while we officially proclaim these former colonies to be free, independent, and sovereign. There appears to be some inherent need to maintain that illusion at all costs.