After Israel assassinated Sheikh Ahmed Yassin, the founder and spiritual leader of Hamas in Gaza on March 22, 2004, John Negroponte, the U.S. Ambassador to the UN, said that the United States was “deeply troubled by this action by the Government of Israel.”

Britain’s Foreign Secretary Jack Straw (representing the U.S.’s closest ally in the war in Iraq) went further and said that Israel “is not entitled to go in for this kind of unlawful killing and we condemn it. It is unacceptable, it is unjustified and it is very unlikely to achieve its objectives.”

A decade later, so-called targeted killing is no longer a counter-terrorism tactic favored mostly just by the Israelis — it has become a tactic of choice both for the U.S. government and for groups and individuals linked to Al Qaeda.

When Barack Obama took office in 2009, he entered the White House with the promise of ending the wars in Iraq and Afghanistan and closing down Guantánamo Bay, but with no hope of being able to credibly claim victory in the war on terrorism, he opted to replace boots on the ground with drone warfare.

He seemed enamored with the technique’s precision, its futuristic glamor and the fact that it would have an even less impact on the lives of ordinary Americans — lives already far removed from the effects of foreign wars. A drone war was a war that America could conduct with very few Americans needing to leave home or even pay much attention.

War was going to shift from shock-and-awe to background noise with drone strikes occurring like lightening strikes in a storm too distant for any American to hear the thunder.

The use of targeted killing apparently no longer deeply troubled the U.S. government. But the tactic that was supposed to finish off Al Qaeda seems to have had the opposite effect.

The U.S. might at this point retain close to exclusive control over deadly drone warfare but it has neverthless created an easy to imitate model of targeted violence where the claimed legitimacy of the violence is not defined by its instruments or the authority of its perpetrators but simply by the idea that the targets are not innocent.

Following the Charlie Hebdo killings, the unity of “Je suis Charlie” in France is meant to show the terrorists that they cannot win, but in as much as Cherif and Said Kouachi and Amedy Coulibaly hoped to be of influence, I doubt very much that they cared about broad public opinion. Their target audience, narrow yet widely dispersed, readily accepts the idea that a war defending Islam can legitimately strike “blasphemers,” security forces, Jewish, and political targets.

Terrorism is redefining itself, shifting away from the use of indiscriminate violence in preference for precision targeting.

Analysts in the media have generally ascribed this shift to a matter of expedience — it’s easier to buy guns than construct bombs. But true as that might be, I suspect the shift has more to do with an ideological shift which springs from the desire to widen the recruiting base of future killers.

Killing innocent people is very hard to justify in the name of any cause. Moreover, to hold ordinary citizens accountable for the actions of their governments isn’t a particularly persuasive argument when universally people feel like they have little influence over the affairs of state.

Just hours before the Kouachi brothers were killed, a Frenchman identified in the media simply as Didier was greeted by one of them at the entrance to the print shop in Dammartin-en-Goele where they had taken refuge. As he left, the gunman said, “Go, we don’t kill civilians.”

This seems to now be central to Al Qaeda’s message: we are not indiscriminate killers.

When President Obama ordered the killing of Anwar al-Awlaki, no doubt he believed his decision was legally defensible and morally justifiable, but in the eyes of Awlaki’s supporters this action must have reinforced the notion that anyone can claim the right to kill when they are convinced that their victims deserve to die.

U.S. Attorney General Eric Holder last week reiterated what have become frequent warnings about the rising threat from “lone wolf” terrorists — those whose actions are impossible to anticipate.

But the lone wolves are not out committing random acts of violence:

A new ISIS video released last week warned: “We will expand across all of Europe, to France, Belgium, Germany, Switzerland and also the USA… I say to my brothers, if you see a police officer — kill him. Kill them all.”

(The same video also encouraged killing “all infidels that you see in the streets” — an indication that ISIS still has a predilection for old-school, indiscriminate, mass violence.)

Over the last year, as government and security officials in Europe and North America have made increasingly frequent warnings about the dangers posed by Western fighters returning to their home countries from Syria, bringing the war with them, I have been among those who thought the threat was being exaggerated.

The flow of fighters appeared to be going overwhelmingly in the opposite direction and if a few returned home, it seemed much more likely that their decision would be precipitated by disenchantment with jihad rather than the desire to take their fight to the West.

The evidence now suggests, however, that the official warnings were not the kind of fear-mongering that commonly and cynically gets ascribed to nothing more than the promotion of an ever-expanding national security state.

When 80,000 security personnel get deployed to hunt down two men, it’s easy to argue that this kind of response amounts to a massive over-reaction. To a degree, that seems true, yet police and other domestic security forces do actually find themselves in a situation for which there are neither parallels in conventional law enforcement or even earlier forms of terrorism.

Even so, as Hans-Georg Maassen, the head of Germany’s domestic intelligence service, said on German public television this week, “we must be calm and master the situation with a sense of proportion. Panic and hysteria don’t help.”