Osama Bin Laden was shot and killed by US operatives in Pakistan on Sunday
Bin Laden changed the world. His will, his hatred-driven actions dramatically altered the foreign policy of the world's only superpower for a decade. The question remains if his death allows new endings.
There's the "
war on terror". The term was decisively rejected by Obama, and the British governments following Blair. But it is worth thinking about.
Critics sneered there could be no war on an abstract noun. A real "war on terror" would have been an interesting, bold and perhaps foolhardy reaction to the attack on America.
A declaration that FDR was right - that
there was nothing to fear but fear itself - that a great people should not cower before a single act however dreadful, that the statistical improbability of being killed by extremists was still very high, could have robbed the terrorists of the reason behind their act, at the price of complacency that could allow further such attacks.
The more grammatically accurate "war on terrorism" was
what was in fact adopted. It allowed an umbrella approach to America's enemies and drew a connecting line between their ill will to merge them into an
axis of evil.
It allowed the Russians and Chinese to identify those in violent opposition to their rule as part of the same problem. It conflated a metaphor for an overwhelming national focus of intention and resources on combating a problem, like a war on drugs or a war on poverty, with an actual war involving, killing, invading and holding territory by military means.
By doing so it increased America's sense of vulnerability and made it even feel, against all the objective facts, like a nation under siege, in real threat of being overwhelmed and extinguished.
Some claimed this was a power grab, that gave the government the authority to do exactly what it pleased. While the strong military response was not what the terrorists wanted, it did inflate their self importance and converted them from criminals into one side in a war.
But, whether you call it a war or not, it is clear modern governments have to remain vigilant against terrorism. Terrorism is a product of technology and to a much lesser extent mass communications.
Rise of 'terrorism' 
There has always been asymmetrical warfare. A grouped of armoured knights raging through a village of peasants with only pitch forks and a rusty axe is pretty one sided. It is only when explosives allowed villagers to creep into the soldiers camp and blow them to kingdom come that you get something like terrorism.
In fact it is only when explosives became so light and powerful that easily concealable and transportable amounts could deal large scale death that you got terrorism.
I like to be pretty precise about such definitions. To me terrorism is the use of violence against a civilian population, by a group that is not acting on behalf of a state, in an attempt to instil such fear that a government is forced to change its policies.
Concealable bombs have been used by terrorist organisations in suicide attacks around the globe
This is not perfect. It excludes attacks on purely military targets. It excludes acts sponsored by a state. It excludes bombing raids on cities during a war, intended to make the enemy surrender, purely on the grounds a state is doing it. It seems to exclude acts of wanton nihilism. Still it is better than nothing.
By this definition terrorism is not going to end with the death of one man. Al-Qaeda is unusual in that it is driven by a global ideology rather than territorial ambitions.
Most terrorist groups have been trying to get rid of those who they believe are occupying soil that is rightfully theirs. Bush and Blair were probably right to worry that technological advances, such and nuclear and biological weapons, and the existence of groups willing to use them, raised the threat of terrorism to a whole new level.
Given that regional and ideological conflicts and further advanced ways of killing lots of people are not going to change, that war will never be over. So perhaps it is best not to call it a war at all. We after all should be vigilant about asteroid strikes and deadly viruses as well.
Labelling terror The professorial president likes precision, and he changed the name of what America was doing to the war on al-Qaeda.
Clinton and others have been careful to say the war is not over.
Wars on organisations, like wars on countries, can be won. But victory may be just as hard to define. The jargonish aim is to "degrade" al-Qaeda to such a point that it is no significant risk.
It has struck me forcefully that there have been very few demonstrations about Bin Laden's death. That does not mean his supporters will not plot terrible revenge. But it does suggest that this leader of a supposedly global movement that wants to inspire people from Bradford to Bangladesh, did not have such a big fan base.
Certainly the protests we have seen were nothing like the recent reaction to the Koran burning, or, some years ago, to the Danish cartoons.
Of course, the new threat seems to be individuals acting alone, inspired by Bin Laden's ideology, but not part of even a loose organisation.
President Obama still faces many challenges on the war on terrorism
People have been arguing for years that the Base (what Al Qaeda means) was a database, a network, way of putting like-minded people in touch with each other, rather than an army.
Those who know more than me say
Bin Laden's death is a second blow, after AQ's impotence in the Arab Spring. I suspect Jihadism, the reaction against the West's dominance, a most postmodern revulsion at modernism, will not go away. It may fade for a while and resurface in another guise, with another name, or under new leaders under a old banner.
This could take a couple of months. It could take a couple of generations.
Obama's war against al-Qaeda is not won. There could be terrible reverses: a handful of people can do awful damage. But Bin Laden's death probably marks a pause.
America is a more martial society since 9/11, with a huge respect for its armed services but weary of war, metaphorical or actual. Drones and special forces are, in any case, the weapons of this war.
That old liberal bumper sticker: "Support our troops: Bring them home" has a new relevance.
Prince William holds hands with his new wife, Kate Middleton, at Buckingham Palace the day after their royal wedding on Saturday (April 30) in London, England.
