Traditionally, one of the strongest arguments for the allied deployment in Afghanistan was that it kept us safe.
The argument was a simple one: Afghanistan had played host to bin Laden and Al Qaeda in the run up to 9/11. Left alone, the country would continue to be a 'safe haven' from where terrorists could plot attacks against the West. Our presence there denied the terrorists of the space they needed to plan new attacks on us. In the years immediately following 9/11, you barely heard a whimper of opposition to this argument. And as politicians kept repeating the mantra that our troops in Afghanistan were "keeping the streets safe" from terrorism back home, the argument settled into the rigor mortis of a political orthodoxy as well.
But the argument no longer works.
Terrorists, it turns out, don't just train in Afghanistan. They also train in other places. Places where we -- or are allies -- have no troops, and where we have no plans to send any.
Nine years into our deployment in Afghanistan, and it seems that whilst the number of attacks aimed at British targets coming from Afghanistan or Pakistan has fallen, more are now emanating from another ungoverned space: Somalia.
The Guardian last week wrote that "British officials believe Somalia is now a more serious base for potential attacks than Yemen." Jonathan Evans, the head of the British Security Service MI5, was quoted as saying that "Al-Shabaab, an Islamist militia in Somalia, is closely aligned with al-Qaida, and Somalia shows many of the characteristics that made Afghanistan so dangerous a seedbed for terrorism in the period before the fall of the Taliban." He went on to make clear that he was "concerned that it's only a matter of time before we see terrorism on our streets inspired by those who are today fighting alongside al-Shabaab," in Somalia.
The message -- from the man whose prime job it is to keep us safe, free from political considerations -- is clear: Terrorism moves. Terrorists are not fussy where they base themselves. Whatever resources we throw at preventing terrorists from planning and training in Afghanistan, they will find somewhere else to do it. Terrorism, in other words, is subject to the 'balloon effect'. If you try to squeeze it in one place, it will merely bulge out in another.
This has, I believe, important implications. It severely discredits one of the key justifications for staying in Afghanistan. Despite the best efforts of our brave Forces, what we are in fact doing is giving the terrorist threat an incentive to move somewhere else. And now we have the evidence that it is doing so.
But this shouldn't have come as a surprise. Before he worked from Afghanistan, Osama Bin Laden had been based in Khartoum, Sudan.
The flaw in the logic of deploying troops in countries to prevent their becoming terrorist havens is that ultimately, it is incredibly short-sighted.
If the trend of an increasing number of attacks coming from Somalia was to continue, what would be the allied solution? Another 200 billion dollars a year? It simply does not make sense to go around occupying countries and trying to rebuild them, paid for by Western taxpayers. Quite apart from the stunningly low return on their investment in terms of safety, it is, even on its own terms, not likely to genuinely deny terrorists the safe havens that it was intended to.
It just means they have to move.
Azeem Ibrahim is a Research Scholar at the Kennedy School of Government at Harvard University, Member of the Board of Directors at the Institute for Social Policy and Understanding and Chairman and CEO of Ibrahim Associates.