An unmanned U.S. aerial vehicle — or drone — reportedly killed eight people in rural Pakistan last week, bringing the estimated death toll from drone strikes in Pakistan this year to 35.

As the frequency of drone strikes spikes again, there are some questions: How many of those targeted were terrorists? Were any children harmed? And what is the standard of evidence to carry out these attacks? The United States must provide answers, and Congress has a critical role to play.

The heart of the problem is that our technological capability has far surpassed our policy. As things stand, the executive branch exercises unilateral authority over drone strikes against terrorists abroad. In some cases, U.S. President Barack Obama approves each strike himself through "kill lists." While the president should be commended for creating explicit rules for the use of drones, unilateral kill lists are unseemly and fraught with hazards.