Two men this week hacked a British soldier to death in broad daylight on the streets of London, hitting the soldier with a car and then nearly beheaded him with a machete, demanding that passers-by film their justification for the attack.
This would be shocking enough were it an isolated incident. Instead, it reflected a 15-year trend of Islamist militants attempting to kill Western soldiers on their home soil.
Such attacks have occurred throughout Europe -- for example, Mohammed Merah shot and killed three French soldiers last year -- yet the two countries in which the threat has been most pronounced have been the U.S. and the U.K.
In the last eight years, there have been thirteen separate plots specifically targeting the U.S. military -- over one and a half per year. Britain has suffered from four separate plots. The attacks differ in terms of scale, strategy, and success, but all have been relatively simple plots aiming to kill.
Some attacks have been spontaneous. When Abdulhakim Muhammad realised he was unable to attack his preferred targets, on June 1, 2009, he used a rifle to shoot two U.S. soldiers who happened to be smoking outside a military recruiting center in Little Rock, Arkansas. One subsequently died.
The other plots required a greater level of planning. This was certainly the case when, in 2003, Sergeant Hasan Akbar used rifles and grenades to kill two soldiers at a U.S. Army camp in Kuwait.
Notoriously, Major Nidal Hasan then killed 13 at the Fort Hood air base in Texas in November 2009. Hasan had contacted -- and taken direct ideological inspiration -- from al-Qaeda cleric Anwar al-Awlaki. Using this attack as a template, in July 2011, U.S. Army Private Naser Abdo was arrested near Fort Hood for a planned shooting and bombing campaign.
Therefore, the attacks that have led to the most casualties within the U.S. military are carried out by members of the armed services themselves.
When attacks are not carried out by U.S. soldiers, they are instead planned by radicalized cells looking to attack military bases. Cells in both New Jersey and North Carolina attempted to launch such terrorist attacks. Yet the larger the cell, the more they were prone to infiltration; and government informants and undercover officers have consistently thwarted plots involving larger networks.
However, even operating with great secrecy is no guarantee of success. Parviz Khan had attempted to keep his 2007 plot to kidnap and behead a British Muslim soldier secret even from members of his own terrorist network.
Yet the plan -- which had apparently received approval from al-Qaeda -- was still rolled up by the British police. Khan and an accomplice, Basiru Gassama, were subsequently jailed.
Others failed because of their amateurish approach. The very first Islamism-related offense prosecuted in U.K. courts was an ultimately failed petrol bomb attack on a reservist base carried out by Amer Mirza in 1998. Mirza was a member of the now-banned al-Muhajiroun, a group that Michael Adebolajo (one of the London assassins) was also connected to.
Most militants attack service members for what the institution represents, and it is rare that a particular soldier will be targeted. There is only one case of this: In 2005, when Abu Bakr Mansha plotted against Cpl Mark Byles, a British war hero who served in Iraq. Mansha had acquired a firearm, Byles' former address, a range of jihadist material, and a newspaper article outlining the soldier's achievements.
The Byles case helps explain why soldiers are so often targeted. It is a response to the frustration radicalized Westerners feel at being either unable or unwilling to travel to countries such as Iraq or Afghanistan to fight jihad.
Among all those who had targeted soldiers in the West, barely any had actual experience of actually fighting jihad in foreign lands. This lack of jihadist credentials abroad is significant in persuading them to try and fight soldiers at home.
Plots against soldiers have been most successful when carried out by those already embedded in the Army, by extremely small cells, or by radicalized individual actors.
The first of these is perhaps the most preventable: the U.S. Armed Forces are especially sensitive to the signs of radicalization following the Hasan shootings. However, small cells and lone wolves pose a much greater problem. The operations are so simple that they are virtually impossible to stop. All that was needed to instill fear in London was a car and a machete.
Ultimately, this also means the militants planning these attacks can only be of limited danger. They are rarely connected into a terrorist network, and their plans are often amateurish. Most rely on a high amount of firearms, as opposed to bombs, meaning that casualties are not likely to reach 9/11 levels.
However, as was shown in London, it does not take a high amount of casualties to terrorize and scar a nation. This was terrorism at its simplest and most replicable. It has to be hoped that it does not inspire others to launch follow up attacks. Yet even if it does not, the past 15 years have shown that the threat to soldiers will not end with their duty abroad.
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