Mark Steyn called it, ten years ago, in his book America Alone: The End of the World As We Know It. In 2005, Steyn predicted with startling accuracy the perilous situation the world now finds itself in with radical Islamic jihadism.
If you haven't read it, you should. I read America Alone when the book was first published, and I enjoyed Steyn's sparklingly humorous writing style as much as I learned from the facts and research presented in its pages. It's disconcerting to see that modern history is unfolding quite similarly to what Steyn foretold over a decade ago.
Steyn's later book, After America: Get Ready for Armageddon was published in 2011. It is a lengthier, more in-depth, more concerning forensic of the dire consequences facing the world in the wake of American withdrawal. I read that book, also, and I'm sorry to say that Mark Steyn was correct again. We are today witnessing, actually living and dying in, the results of the USA "leading from behind." Unsurprisingly, it's neither a safe place nor a pretty sight.
No one knows what the future holds. But we can be reasonably certain that it will be much more difficult than it should have been, had we only heeded and acted upon obvious warnings.