When: The US has been attacking targets in Northwest Pakistan using drones since 2004. The strikes started under the presidency of George W. Bush, and surged during Barack Obama's terms in office. In May 2014, US authorities announced the end of the "targeted killing", with the frequency of the strikes significantly decreasing in subsequent years. But although the scope of the attacks has been limited, they still go on a case-by-case basis. For instance, the US has carried five airstrikes on Pakistani soil in 2017, according to The Bureau of Investigative Journalism (TBIJ).
Number of strikes and casualties: The strikes have claimed the lives of about 400-900 civilians (over 200 of them were children). The number of people killed as result of 429 airstrikes ranges from about 2,500 to over 4,000 victims, as reported by various sources, cited in the TBIJ database.
Did the operation help to achieve intended goals? Partially. Many senior members of terrorist groups were killed, but the terrorist organizations themselves are still active in the country.
When: The US started "targeted killing" using unmanned aircraft on November 5, 2002 almost one year after the notorious 9/11 terrorist attacks. The operation is still underway, with the most recent strike taking place on October 25, 2017.
Proclaimed goals: The military operation is aimed at destroying Al-Qaeda terrorist cells. The first strike targeted the then leader of the Yemeni branch of the terrorist group Abu Ali al Harithi. In 2007 the Yemeni and the Saudi branches of the group united into one organization, which has since been the focus of US operations in Yemen.
Number of strikes and casualties: The US has carried out a minimum of 259 airstrikes since the start of its military operation in Yemen. The attacks have killed between 892 and 1,238 people in total, including 166-210 civilians. Almost 50 of them were children.
Did the operation help to achieve intended goals? Somewhat. Many Al-Qaeda leaders were eliminated, but the group is still active in the country.
Proclaimed goals: The strikes are part of the US global war on terror. They target the Al Shabaab armed group and other military formations.
Number of strikes and casualties: A minimum of 60 drone strikes were carried out by the US on the territory of Somali. The total number of reported casualties ranges between 343 and 510. The attacks claimed lives of about 10-38 civilians, among them there could have been children.
Did the operation help to achieve intended goals? In some measure, yes. Some attacks on Al Shabaab targets managed to eliminate major members of the group, but the organization itself continues to operate in the country. The UN-mandated Amisom military force, however, managed to push armed Al Shabaab out of the country's capital of Mogadishu.
When: US drones have been attacking terrorist targets in Afghanistan since late 2001 and may continue beyond 2017, according to TBIJ.
Proclaimed goals: The military operation has been targeting several armed groups in the country, such as such as the Afghan Taliban and the Pakistani Taliban, as well as Al Qaeda and Daesh.
Did the operation help to achieve intended goals? Counter-terrorism strikes have been slightly successful, but the armed groups are still conducting their activities on Afghan soil.