UN investigator Christof Heyns issued a report to the United Nations Human Rights Council ahead of a debate it’s scheduled to have later today, in which he called on the US to please explain the rash of drone killings which have escalated under President Obama, killing civilians along the way.

Reuters reports: “Citing figures from the Pakistan Human Rights Commission, he said U.S. drone strikes killed at least 957 people in Pakistan in 2010 alone. Thousands have been killed in 300 drone strikes there since 2004, 20 percent of whom are believed to be civilians.”

The report highlights an apparent foreign policy doctrine of the Obama administration: keep a low profile while escalating attacks. Stateside, the Obama administration’s image has benefitted from troop drawdown, which have certainly limited the exposure of US troops to conflict. Nonetheless, the human toll of our war on terror continues to mount.

Secretary of State Clinton recently defended the drone attacks when one killed a high-level Al Qaeda operative Abu Yahya al-Libi.

However, rebuts Heyns, “While these attacks are directed at individuals believed to be leaders or active members of al Qaeda or the Taliban, in the context of armed conflict (e.g. in Afghanistan), in other instances, civilians have allegedly also perished in the attacks in regions where it is unclear whether there was an armed conflict or not (e.g. in Pakistan).”

He notes that international human rights law dictates that before individuals are fired upon every effort must be made to arrest them, taking into consideration “principles of necessity and proportionality on the use of force.” He says the Administration has failed to consider such principles. Of course, “necessity” is a highly debatable term, which will likely be debated ad nauseum.

“Thousands of innocent people, including women and children, have been murdered in these indiscriminate attacks,” writes Heyns.

Though he’s maintained his “buddy” image, Obama turned out to be way more of a hawk than Bush-era conservatives were expecting. Now it looks like he’ll have some explaining to do to those who weren’t prepared for it.