Should everyone withdraw completely? No. We do, however, need to start focusing less on them and more on the well being of our own country. The intentions of the government to help an support struggling countries in the middle east are just and of good nature, but honestly, we're giving more than what we get out of it.
For the sake of simplicity and ease on my part, I'm going to use statistics mostly about the United States and their involvement because frankly, I don't know what the level of involvement for the UK or any other European country is. National debt is currently above $14 trillion with a rise of nearly $4 billion a day. In the budget for 2010, "the president's base budget of the Department of spending on 'overseas contingency operations' [brought] the sum to $663.8 billion." With those estimates, about half of the yearly rising national debt is equal to the costs of military foreign and affairs. That's outrageous if you ask me. Now clearly, that doesn't mean translate to half of the total debt consisting of foreign affair costs, but it's a huge thorn in the side for the economic advancement of the United States.
So with all that said, here's my answer in a nutshell: Keep a good number of troops in the middle east for moderation purposes, but not enough to make it so that we keep throwing money down the toilet. Money can be saved by cutting spending in foreign affairs as well as other programs. And if our goals are to protect, we don't need to supply as much funding as we currently are. They have governments over there too (except Libya, lol!!), and it's time for the world's superpowers to stop playing the overzealous parent role in order to focus on our own problems.