Actually, there has been these conflicts throughout American history, and before that they came throughout Eurpoean history. Each one sows the seeds of the next, in some way. WWII directly resulted from the decisions made at the end of WWI, while the Korean War and Vietnam War arose from the decisions made at the end of WWII. A good book on the subject is In The Ruins of Empire, which chronicles the conflicts that arose after the Japanese defeat in places such as the Philipines, Vietnam, Indonesia, Korea, and China. However, if you add in Grenada, then you really have to add in all the very similar, and closely related, actions that the US took in the area for a couple centuries. The book The Savage Wars of Peace, shows that these conflicts have been nearly perpetual. Peace is relatively rare.

If you go further back, you can see that what the US calls the French and Indian War led to the Revolution, which led to the War of 1812. It all ties together in some way, though some wars tie more strongly to others than the rest. Still, conflict is the only real constant, and anybody who goes looking for relationships between the sequences of wars will find those relationships.