I'm voting for numb on this one because there are two answers to the question, no & yes.
No they should have never entered Iraq it was a highly illegal invasion. People believed it was for the good of the Iraqi people but isn't there countries worse off that need our help?
Yes they should be there simply because of exactly what G10 said, things would be worse if they did pull out. BUT, there again its only causing a vicious circle. The longer they stay there the more hate is built up from the ever growing population of the enemy.
Its extremely hard to solve a religious conflict and the U.K. only know that too well with being stuck in the middle of our own troubles here for over 30 years.
For one thing they are in it for the long haul and lots more lives will be lost.