For years, the U.S. tried and failed to stop North Korea from advancing its nuclear and ballistic missile programs. Now the U.S. faces a growing threat from Pyongyang and has few good options because of those nukes. Think the mullahs in Iran haven't noticed? Yes, the Iran nuclear deal begins to taper off after several years. But while it's in place, international inspectors monitor Iran's compliance and can presumably detect any moves it makes to break out and build bombs.