Sources: Sen. Rand Paul [PDF], [Press Release], Sen. Wyden, et al.
quote: A country like Yemen is obviously a different overall situation than the US. There is no allied police force, FBI, etc in Yemen to go to as first options like there is in the US.
quote: Take Timothy McVeigh...if the authorities had known about his plot while he was sitting at his house with the truck loaded up, they wouldn't have used a drone strike, they would have gone in with a bunch of FBI, SWAT, or whatever. But once the truck was rolling, if one way to stop it for sure was a drone strike, then a drone strike would be an option.
quote: What happened in Waco wasn't right, and there was fallout from it if you don't recall.