It very well could. I don't claim to know troop deployment in Iraq but it could easily be the British troops coming home are deployed in an area of less importance, and area where the local Iraqis have gained control or an area near major ally troop concentration.
We may never know for sure but why does the left ALWAYS look at the dim side? It's true that the right always looks at the good side, but isn't that better in the long run? Aren't we, again, encouraging the enemy to fight harder by saying the British have had enough and leaving? If we knew this for a fact it would still not be in our own troops best interests to tell the enemy.