Who determines what an "imminent" threat is?
When the decision process on these drone strikes is completely opaque as it is, the higher ups basically get to kill whoever they think is a threat.
Not only that, but arguing that you are fighting an idea like terrorism gives you carte blanche to wage an unending war of your choosing regardless of whether or not that war makes us ANY safer in any quantifiable way. Also, fighting terrorism allows you to chase it to whatever country you like.
So basically, our government has given itself justification to kill people wherever they like because they decide they want to without any oversight.
The relative levels of collateral damage between torture and drone strikes aren't even comparable.
The nature of drone warfare has taken all political risk (the only kind the decision makers care about) out of lethal military action.
How is killing 1000's with no oversight better than torturing and killing a small number (with vastly less collateral damage) with an actual justifiable reason (the need for actionable intelligence)?
Your argument is like trying to pick up a bucket you're standing in.
I'm worried more about the growth of executive power that allows the president to kill anyone anywhere just because he finds it necessary, than I am about the US torturing prisoners for actionable intelligence.
The only way your argument works is if you think Obama's capability to determine who is a big enough threat to assassinate is completely infallible always.
I can't place that much faith in anyone.