This may seem obvious, but the UK should stay out. SO should the rest of the "west".
There are plenty of people calling for intervention, and not only from the west. But my opinion is that we should stay out.
We don't have a good track record - recent examples and Iraq and Libya, but this goes all the way back to World War 1.
Well, I should rephrase that - we don't have a good track record for the people living there. I am sure prestige was gained and riches obtained in them all.
Another thing to remember is that when you go to war, there is always a reaction.
Currently we are already involved in bombing other countries but as any random person and they will not think that we are in a state of war. Any retaliation is perplexing, "why are they attacking us? it is because of our freedoms?" no its because the UK is carrying out bombing campaigns in foreign lands.
Syria is a mess right now and ISIS are the perfect bogeyman who revel in beheadings and murder as propaganda.
However, they are the second worst group in Syria - Assad and his regime have killed, massacred and maimed at a level that ISIS can only dream of. Chances are that to fight ISIS, the UK will consider siding with Assad's regime.