Yes I will help you :)
My opinion is that they have done and are doing what they are supposed to.
In the middle east tyranny has been stopped multiple times and yes maybe our motives are questionable, but at least it has made the lives of the peoples in the countries we are in better as they are no longer subjected to unjust medieval style punishment and new governments have been set up to lead these countries into the modern age.
Many people focus on the current main conflict in Afghanistan forgetting the Royal Navy who stop pirates around Africa or the Royal Airforce who do search and rescue aswell as flying aid missions. We also have the troops at home who help out on emergencies or even generally where they are needed, in major floods they help and in other instances where there isn't enough manpower they muscle in, there is also how we have all sorts of military displays often viewed for free by the public.
I respect our military as without them we would probably be a lot worse off than we are with them, they put thier lives on the line for relatively low pay allot of the time thier own motives as member of the armed forces is to protect thier country, which I highly commend.
Combining military forces is hard as countries have different goals and motives often making it impossible to do so, I mean we could try to ally with Iran but that would in turn destroy relationships with other allies, so we may as well stand where we are in these terms.
As for a certain unnamed comment highlighting how we apparently don't do polls and homework I find it odd that a 'top contributor' wouldn't know that we have categories for all of these, I never heard of any ruling against opinions and I rarely see an answer without and as for blogs this doesn't relate to the question anyway and it is near on impossible to blog on Yahoo answers.
Therefore your answer... Is an opinion! :o