What evidence there is? When they were declared guilty by a court? When they were charged with a.crime.in first place?
To which I respond:
> We have not declared war on Yemen or Pakistan.
Which means that our military actions in Yemen or Pakistan are illegal. This is still ignoring other obvious questionable points about drone strikes, such as issues regarding proportionality.
No one in Yemen is waging war on the US, that's a construct of the creative imaginations of a bunch of people that stand to profit from having a bogeyman so they can sell their toys.
The people in the tribal lands of Yemen can't wage war on the US since:
(1) they don't have air strike capabilities able to reach the continental US
(2) they don't have a shared border where a land war could be waged
(3) they don't stand a chance of getting a boat in US coastal waters Yemeni people or people residing there are not waging war on the USA.