In 2009, President Obama's first year in office, the tempo of such attacks in Pakistan increased 47 percent, to 53. The vast majority of these have been carried out with drones.
Tuesday's strike brought this year's tally to 12, with just over 100 fatalities. That's just under a quarter of last year's total. If that pace were matched for the rest of the year, there will be 134 US attacks inside Pakistan.
Conflicting public claims
The Long War Journal says that 258 militants and 31 civilians were killed in these attacks in 2007, while 463 militants and 43 civilians were killed in 2008. It reports no civilian casualties so far this year.
To be sure, there are frequently conflicting public claims about the number of civilians or militants killed in such attacks. On a number of a occasions, senior Taliban or Al Qaeda-linked figures have been reported killed, only to emerge on videotape later to say reports of their demise were exaggerated. Hakimullah Mehsud, the current leader of the Pakistani Taliban, was once reported dead – and then made a public appearance in good health. US officials now say they're confident that he was killed by a December drone strike. His predecessor, Baitullah Mehsud, was killed by a US drone strike in August, 2009.
Two of the men vying to replace him at the head of the country's Taliban movement have also been incorrectly reported as dead in the past.
Strikes controversial among Pakistanis and in strategic circles
The drone strikes have been controversial in Pakistan, where many average citizens view them as an extra-legal violation of national sovereignty by the US, which may be a key provider of military and economic aid to Islamabad but is still viewed with suspicion by millions of the nation's citizens.