We usually expect North Korea to be all talk when it comes to weapons technology, but South Korea warns that its reclusive neighbor’s latest rocket launch suggests Pyongyang may be capable of launching a warhead 6,200 miles—putting the United States’ West Coast within range. According to U.N. sanctions, North Korea is banned from any type of missile or nuclear-technology testing, so this month it simply sent a weather satellite into orbit. But critics aren’t buying it, suggesting that the satellite launch was just practice for doing the same with a nuclear warhead. South Korea retrieved parts of the rocket that fell into its waters and, after testing its materials, determined that North Korea had secured a range of over 10,000 kilometers (6,200 miles) for a warhead between 500 and 600 kilograms in size—that’s roughly 1,100 to 1,300 pounds.