Say what you will about the legality, accuracy, or long term prudence of drone strikes on foreign soil, drone strikes are likely the most effective military strategy in recent times. People lose sight of what's important in the drone strike debate: that drones allow for precision that would otherwise be only accomplished by soldiers on the ground.
The question depends how you define effective - and for every reason other than killing multitudes of people (innocent or not) without the perpetrator having any literal blood on their hands - drones are ineffective in the fight against terrorism (which is what they are being used for as stated by US foreign policy and US president Obama). The inhumane and barbaric use of drones- which are killing civilians - WILL inspire revenge attacks and increase terror motivations and anti-west causes. Just look at everything that has resulted from the war on terror.
I believe that drone strikes are not an effective weapon in the "war on terror". Drone strikes only further hostilities and add to the "tit for tat" escalation. Individuals who have committed crimes against the United States should receive a fair, speedy trial. Unsanctioned air strikes from unmanned drones is an act of war.