"Do not be wise in your own eyes. Fear the Lord and turn away from evil."
The Septuagint has do not be wise and sensible and prudent to yourself. Don't be impressed with your own ability to navigate this world. The world is a far more complex place than you can figure out. Your own landmark's signals and tests will fail you. You must fear the Lord and realize that only God knows the proper boundaries and ways through various problems and situations. He knows how to live in this world He created, and He knows what not to do.
It is a sad thing when an individual – let alone a nation – thinks that it is beyond the direction, wisdom, and boundaries of the Almighty. It is headed into destruction. For the world is a far more complex place than we can possibly imagine. No mortal has it wired.