These 7 maps explain US strategy
This is a simple, straightforward explanation of US security strategy from the revolution to the present. You really should read it all, it has a wealth of understanding, and it is written in an engaging readable style.
Notice how our 21st century strategy is little more than a derivative of our Cold War strategy, leading us to continually act against our current interests.
When you are done, head over to this article on Mapping Russia’s Strategy. Written by the same author, also with a wealth of understanding.