In a sense, we've been in a state of war with North Korea for nearly 70 years. We never signed a peace treaty, and we left troops on the Korean Peninsula to enforce an armistice. In terms of time, that's a big expense, but it's cheap when measured in the more important currency of human life. Similarly, the Cold War was not simply a metaphorical war. We spent American blood and treasure for nearly half a century containing the Soviet Union around the globe. But we opted not to have a direct confrontation because we thought biding our time was a better alternative than a direct confrontation costing millions of lives.