_{Militant Islamic State fighters parade on military vehicles along the streets of Raqqa (Reuters)}

In the wake of the murderous massacres in Paris, the demand for violent retaliation against Islamic State (IS) is gaining momentum. David Cameron now plans a renewed bid to secure parliamentary approval for UK air strikes against IS in Syria.

At one level, this is an understandable reaction to the fascist-like tyranny and brutality of IS. But understandable reactions and effective reactions are often two different things. The desire for retribution, no matter how seemingly justifiable in response to the slaughter of so many innocents, is not a sound basis on which to frame political and military policy.