On the 15th of June 2015, it was announced that a US drone strike killed Nasir al-Wuhayshi, leader of Al-Qaeda in the Arabian Peninsula (AQAP). Operating predominantly in Yemen, AQAP have since executed prominent member Humam al-Hamid, and three other men suspected of being spies. AQAP claims that Humam al-Hamid disclosed Nasir al-Wuhayshi's location to the US intelligence services.

It is difficult to establish whether Humam al-Hamid was actually a spy, with the only available evidence being rumours spread by jihadists on social media. In addition to twitter accusations that Humam al-Hamid was cooperating with US intelligence, accusers also claimed he was working for both ISIS, a rival of AQAP, as well as Saudi Arabia.

Although, Humam al-Hamid was previously a founding member of the Al-Battar Media Foundation, which supports ISIS, Al-Battar have since claimed that they lost contact with Humam al-Hamid many months before Nasir al-Wuhayshi's death.

Understandably, US intelligence have not disclosed whether Humam al-Hamid was an agent, but suggest that his execution demonstrates the strategic utility of drone strikes in creating distrust and paranoia within terrorist organisations. Distrust can create instability within a terrorist organisation, reducing their operational effectiveness. Drones are renowned for the psychological impact they have on the enemy. With apparent omnipresence, drones are capable of becoming lethal at a moment's notice with sophisticated accuracy, and can do so without being seen or heard.

With the inability to fight back or defend oneself, drones have become feared by both terrorists and civilians alike in Afghanistan, Pakistan, Libya and Yemen. Fears of infiltration within AQAP is likely to result in the enforcement of stricter security protocols, which will further hinder their command and control structure.

If accusations of treachery continue, particularly against innocent members, then AQAP's morale is also likely to suffer substantially.

AQAP has a history of executing suspected spies. In 2014, they killed four men who were accused of implanting tracking devices in vehicles that were later destroyed by US drones.

If Humam al-Hamid was a spy, then it would demonstrate operational shrewdness on America's part, to recruit an agent within the region. In modern conflict, the US has tended to rely on signals intelligence, such as monitored phone calls and internet communications to devise military strategy within the Middle East. Having said that, if Humam al-Hamid was a spy, then the US will be disappointed to have not protected such a valuable asset. The US intelligence community, will deny any involvement with Humam al-Hamid, as they will not want to develop a poor reputation for managing and protecting their agents, which would increase the difficulty of recruiting agents in the future.

The US intelligence community will regard the targeted killing of Nasir al-Wuhayshi as a great success.

Firstly, many within US government regard AQAP as a greater threat to US security than ISIS. This is primarily because AQAP have explicitly looked to target the United States, allegedly perfecting methods for smuggling explosives onto airplanes, without alerting airport security screening systems. By contrast, ISIS are more accustomed to inspiring individuals within western states to conduct their own terrorist operations. Secondly, Nasir al-Wuhayshi was a key player within Al-Qaeda, as leader of AQAP since 2008, and Al-Qaeda's global general manager, he was the likely successor to Al-Qaeda's current leader Ayman al-Zawahiri. Nasir al-Wuhayshi was also an inspirational figure to many aspiring jihadists, and his death will be an incredible blow to Al-Qaeda's overall morale.

Whilst US strategists may use the death of Nasir al-Wuhayshi to justify further drone strikes in the region, they must not forget that such decapitation strikes have yet to defeat a terrorist organisation. Qassem al-Rimi has already been announced as Nasir al-Wuhayshi's successor. The power-vacuum left by the death of senior terrorist leader can also fracture the organisation they left behind, creating even more violent and extreme factions. The emergence of ISIS from Al-Qaeda after the death of Osama bin Laden is a clear example of this. Furthermore, drone strikes hold the potential for collateral damage, which can radicalise civilians towards extremist causes. Drone strikes remain a hugely controversial aspect of US foreign policy, and have done little to remedy America's poor reputation in the Middle East.

AQAP are currently in a crisis after Nasir al-Wuhayshi's death. However, this is unlikely to be the end of AQAP's dominance within Yemen, nor the last time that drones will be used to target senior terrorist leaders.