Gordon Mohr of Bitzi writes in to correct my assumptions on suitcase nukes. "An atomic "suitcase nuke" is commonly estimated to be capable of anywhere from sub-kiloton to 10-kiloton blast power -- while being light enough to be carried by a single person. The blast-analysis tool to which you linked considered the effects of a 1-megaton hydrogen bomb, which could be anywhere from 100 to 1,000 times more powerful than a "suitcase nuke" --and I believe would weigh 1,000 pounds or much more." So a 1-megaton attack would require a vehicle the size of a U-Haul. We've had A-bombs; welcome to the U-bomb.