Parliament will probably decide to bomb Daesh in Syria.
The decision is understandable, predictable even.
Terrorists engender more hate than terror in people, and hate is an emotion that demands expression.
Bombs express hatred very well. Tabloid editors and commentators are working up to demanding that Daesh leaders and fighters be taken out, rubbed out, vaporised etc.
The fact that civilians who happen to be (or not, as the case may be) in the vicinity of Daesh operatives are also torn limb from limb, in some cases reduced to quivering lumps of red jelly, in others merely supplied with a PTSD that will blight their life...this fact is regrettable, but necessary because we must bomb.
So the emotional side of the decision is easy to understand.
The rational side of the situation, in other words, what is the best thing to do in response to Daesh's challenge, that is more difficult. It needs valid information and careful assessment. It needs thought,
That is why we should expect Parliament to go for the emotional option.