I found the first three lectures to be generally insightful, logical, and - with the benefit of hindsight - generally proven "correct" by events since the 1950s. The last lecture is incredibly off, though I do not believe that Kennan would have been able to imagine the present world quite as it is. At the very least, he certainly did not have it as context for his arguments. From a strange, dystopian, globalist mindset to a rather naive and immature assessment of migration, Kennan misses the mark pretty incredibly at various points in the final lecture. Certainly worth reading regardless, as it provides great insight into one of the preeminent foreign policy minds of the 20th century.