[عاطف القاضى]

A thousand thanks
I'm assuming you mean within the context of "Would you mind ...?"


... if I smoked ... is more polite. It seems to indicate that you are considering the possibility of smoking, but could be dissuaded if there is an objection.

... if I smoke ... seems to indicate that you are more intent on smoking. It gives the slight impression that you don't expect any objections to the idea.