Two weeks ago, the conflict in Mali seemed like one of those wars in one of those far away places that most people had barely heard of. Yes, an enchanting country with a rich heritage had supposedly become the home of al-Qaeda's first state-within-a-state. But hopefully it wouldn't trouble anyone outside it.
One week ago, as France began its surprise aerial bombardment of parts of Mali, it seemed to feel a tiny bit closer. Some countries expressed their support for President Hollande's operation. Britain helped out by throwing in a couple of military aircraft. But it looked like a token contribution towards someone else's war.
This week in the Algerian desert, as jihadists stormed a BP gas plant, that war became a chilling reality. In deadly and dramatic circumstances, Mali announced itself to the world as a problem that will not go away.
Once again, the kaleidoscope has been shaken, to use the language of Tony Blair following September 11th. And just as 9/11 compelled us to face up to what security services had already known about Osama bin Laden, the siege in Algeria appears to have forced Britain, the United States and others to reconsider the perils in Mali's militant-controlled north.
Of course, it is unlikely that we will see anything like the level of military commitments to Mali that Britain made to Afghanistan after the terrorist attacks of September 2001.
But as David Cameron acknowledged earlier today, the new militant threat presents the world with a global problem which "will require a global response for decades".
But what should that response be? How can complex Islamist networks fuelled by poverty and drug trafficking - not just ideology - be beaten? Beyond a few weeks of bombing, what more can be done to repel the threat?
These questions are not new. Politicians have been quietly asking them for some time, without answers. Meanwhile, the militant threat has grown in countries like Nigeria, Somalia and now Mali - creating a terrorist network which spreads from Afghanistan to the Atlantic.
Many world leaders might feel that now is the moment for greater action to stem Africa's al-Qaeda threat.