The assassination of Osama bin Laden sends out a powerful message: that America's enemies can be tracked down and destroyed however long it takes and whatever the diplomatic niceties.
Anyone who takes up arms against the US must take heed of this - and be prepared to pay the price.
If everything had gone according to Western plans, both bin Laden and Gaddafi would have died within hours of each other.
It seems small wonder that Prince William and Kate Middleton decided not to take a foreign honeymoon at this point and to stay in north Wales instead of holidaying to Jordan, as some reports suggested they planned to do.
This is a dangerous moment, because the message of US and Nato power is being transmitted to a group of people - Islamic terrorists - with a proven appetite for martyrdom, who maintain that death at the hands of one's enemies is more honourable than compromise.
We know a little about that syndrome in Ireland where, for instance, the Irish War of Independence was sparked off by the execution of the leaders of the 1916 Rising, which fanned a faltering cause into life.
There is no easy comparison between the Provisional IRA and the suicidal fanaticism displayed at by al-Qaida on 9/11, but the use of the dead to inspire the living to continue the struggle is a common factor.
Republican funerals have recruited young people to the IRA, so we can understand why the US decided to dispose of bin Laden's body quickly at sea, risking defiance of Muslim funeral rights.
Burial by his family and friends, or even a marked grave, would have risked creating a cult and a world media event.
Even as things stand, this is a singularly dangerous time when the West must play its cards very carefully to avoid inflaming feeling in the Muslim world.
Mossad - the Israeli intelligence service - has also shown the ability to track down and kill its enemies.
In Operation Wrath Of God, which stretched over two decades, it tracked down and killed dozens of alleged Black September activists implicated in attacks on Israeli athletes at the 1972 Olympics.
However, even Mossad's ruthless determination and deadly efficiency did not buy security or deter all future attacks.
The long and bloody conflict continues, fed by the blood of the dead. Black September was flattened, but new organisations now seek to destroy Israel.
So far, things are going reasonably well following bin Laden's assassination. That and the slaughter of al-Qaida leaders by the US drone aircraft in the tribal areas of northern Pakistan has left the organisation on the ropes.
The Pakistani government has supported the US action on its soil. The bin Ladens are a leading Saudi family, but that government has been supportive; welcoming his death as part of a campaign to dismantle terrorist cells worldwide.
Even the Iranian reaction has been muted. Only Hamas has expressed sympathy with bin Laden, describing him as an "Arab holy warrior".
The favourable international reaction provides no grounds for complacency. Opinion can turn quickly.
The US and the West must now be in listening mode. In spite of the recession, we need to extend aid and trade carrots, not just military sticks, to modernising forces throughout the Arab and Muslim world.
Whatever criticisms may be made of Pakistan, it is a nuclear power with a history of political violence which cannot be allowed to become a failed state. The imperative is to deepen its democratic processes and combat corruption to lessen the appeal of extremism to its youth.
The democratic forces in Libya and Yemen cannot be allowed to fail for lack of support or be left to be taken over by fanatics.
All this needs to be done with the maximum co-operation of the Arab League and African countries like Kenya or South Africa.
This is an opportunity to build a new world order in which al-Qaida will, like the IRA, become a thing of the past. There is also the danger of breathing new life and support into the terror network.
Opening new military fronts could overstretch the West's armies and economies without increasing security.
Military power has delivered an opportunity which has - for once - united world opinion, rather than divided it.